#help-49

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twilit jetty
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what name does it have?

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-2 something -1 is the same as -2 subtract 1

sly cape
twilit jetty
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its name is addition

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its purpose is to mix numbers together

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its purpose is not to make them more positive

sly cape
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well addition always have positive affect..

twilit jetty
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no it doesnt

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you can "add on debt" for example

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think of the concept of "more lower"

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addition has the effect of combining things together

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youve been working with positive numbers for so long that you think addition can only ever make things higher

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with negative numbers, this is no longer the case

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think about the rules youre using in the first place to simplify -2 + -1

twilit jetty
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if the + sign must make things larger, then why did you end up simplifying it to a smaller number?

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the rules are correct, you know that

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this is clearly an example where adding -2 and -1 ends up being -3

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before it was -2 and -1, after it was -3

sly cape
#

yeah with negative affect..

twilit jetty
#

yes, and there you can see that addition, or adding, as denoted by the plus sign,

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has just produced a number smaller than what came before it

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this is part of the structure we use to add numbers together

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addition doesnt mean positive

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the unary operator +, as in +4, means positive instead

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youve just mistook one for the other

sly cape
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yeah but adding numbers is getting the results higher but in this case it isnt

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so it is subracting.

twilit jetty
#

well contrary to your beliefs, the rest of the world uses negative numbers and adding them a different way

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having to remove particular aspects that you expect out of certain operators is part of what allows us to use them in very general situations

sly cape
#

theres no need for + to exist in -2 + -1

twilit jetty
#

lets consider for example, -2 + x

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would you say the -2 and x are being added together?

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what?

sly cape
#

nvm

lavish venture
twilit jetty
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you literally just told me earlier on that that is not how we read it

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here

twilit jetty
#

thats dangerous

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what if x is -1?

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would you still call it adding?

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and if the + sign can no longer be called "adding," what else are we going to call it?

sly cape
twilit jetty
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in the expression -2 + x,
would the + be considered adding if the x is -1?

twilit jetty
#

now in the expression -2 + -1, would the + still be considered adding?

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see there, youve changed your mind

twilit jetty
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and this is important: theres an important aspect of math called "consistency"

sly cape
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youre gaslighting me i think

twilit jetty
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Im convincing you that thinking -2 + -1 isnt addition is a terrible idea

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now Im going to tell you how we usually treat these operators, so you can compare the ideas together

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so far youre viewing the operators in terms of what they will end up doing

twilit jetty
sly cape
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okay can we like go back to the topic and not argue what is an addition or not?

twilit jetty
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oval, this is a very important distinction

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both this and the -x^2 are two separate but still important issues

twilit jetty
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you cant just drop one instead of the other

sly cape
twilit jetty
#

does + always have to give you a greater result than before?

sly cape
lavish venture
twilit jetty
#

we would still call it addition, its just no longer an aspect that addition does anymore

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the core difference here is what we decide to keep when -2 + -1 is -3

sly cape
twilit jetty
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youre keeping the "greater than before" part

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we keep the "Im typing a + sign" part

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commonly addition refers to the specific tool, action, symbol, verb, process you are doing

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instead of the output

sly cape
twilit jetty
waxen musk
twilit jetty
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if I add on $2 in debt, how much debt do I have?

twilit jetty
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right,

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now lets say instead I am trying to make a profit, but I've already lost $5

sly cape
twilit jetty
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if I lose an __addition__al $2, I would be -$7 below where I started

scenic wyvern
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may I provide perhaps another viewpoint?

twilit jetty
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try

scenic wyvern
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if I may interrupt, maybe one way of thinking about addition/subtraction and positive/negative numbers is like this.
think about positive numbers as moving to the right on a number line, and think of negative numbers as moving to the left (with right being bigger).
now, addition means to move in the same direction as the number, and subtraction is to move in the opposite direction from the number.

so adding a negative number means to move in the same direction as the negative number = move left.
and subtracting a negative number means to move in the opposite direction from the negative number = move opposite of left -> move right.

sly cape
waxen musk
grand pondBOT
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Cycadellic

twilit jetty
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I dont have strong hopes, but see if youre convinced by hanako's view of addition

waxen musk
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where (-b) is negative b

sly cape
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ill read that in a moment

twilit jetty
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please read it right now

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hanako put some effort into typing it

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you can hear them out at least

sly cape
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but @twilit jetty if you do 6-3 thats also a subtraction

waxen musk
twilit jetty
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that isnt my point, actually

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because it depends on an assumption oval cannot agree with

waxen musk
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oh, sorry

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what is this assumption?

sly cape
scenic wyvern
twilit jetty
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aaaand it didnt even survive past the first hurdle, sorry hanako

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the point here is that oval thinks addition should only produce larger numbers and subtraction should only produce smaller number

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this is true when we are working with positive numbers

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however, when negative numbers are introduced,

waxen musk
twilit jetty
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something needs to be redefined

lavish venture
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the major misconception you're having is that subtraction/division aren't the fundamental operations. we adopt shorthand notation like
x - y which is definitionally x + (-y) where the symbol "-y" is defined to be the additive inverse of y meaning it is the number that when added to y gives 0. we write x - y for notational convenience. addition has nothing to do with getting larger. you'll notice that in your shaky definition of addition you said you mix two things and get a larger thing and i pointed out that multiplying by numbers > 1 has this exact effect as well, as does many other things. maybe learn how addition is formally defined first.

twilit jetty
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I think we have too many cooks here all saying similar ideas

waxen musk
scenic wyvern
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I'll leave it to you folks, sorry for interrupting

sly cape
twilit jetty
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theres a + sign there though

waxen musk
twilit jetty
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brackets can mean more than just multiplication, it could just be to do the first thing you see

lavish venture
twilit jetty
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3 + (-2) is 3 + -2

lavish venture
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๐Ÿค”

twilit jetty
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the - is just to show that the 2 is negative, and thats being done first there

waxen musk
twilit jetty
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next is 3 + -2 to get 1

lavish venture
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happens

twilit jetty
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if you had 3(-2) instead, then that would be -6

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as you can see, theres no operator between the 3 and the -2

sly cape
waxen musk
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exactly

twilit jetty
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cool, lets get back on topic

waxen musk
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3 + (-2) = 3 - 2

twilit jetty
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alright oval what I want to do here is make clearer how we see things

sly cape
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and you change signs only when theres a minus

twilit jetty
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oval theres more to these rules than just feelings

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3 + (-2) isnt "near enough"

waxen musk
twilit jetty
sly cape
twilit jetty
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theres no exceptions here

sly cape
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well you guys are doing it

twilit jetty
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oval

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listen to me

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3 + (-2)

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and 3 (-2)

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an entire + sign is missing

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so theyre different, arent they

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thats like comparing 3 * 2 with 32

sly cape
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yeah but youre putting it in a bracket

twilit jetty
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oval, theres a common way to write multiplication, which is with no symbol at all

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for example, xy means x * y

twilit jetty
sly cape
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ik that..

twilit jetty
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that is where the * comes from

sly cape
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i know that..

twilit jetty
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using brackets is how we can create a lack of operator

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but it is not the only purpose

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brackets can also mean just doing something first

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in 3 + (-2) for example,

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there is still an operator (+) between the 3 and the (-2)

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it does not mean you "transform" the + to a *

twilit jetty
sly cape
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why

twilit jetty
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3 + (-2) has an operator between the 3 and the (-2), which is the +
3 - (-2) has an operator between the 3 and the (-2), which is the -
3 / (-2) has an operator between the 3 and the (-2), which is the /

sly cape
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ok lets go to the point..

twilit jetty
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3(-2) does not have an operator between 3 and the (-2)

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and so we view that as 3 * (-2)

sly cape
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so 3+(-2) is 1 and 3(-2) is -6

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okay

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i get it

twilit jetty
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very good, that trips people up

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theres a good reason for that actually

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often times we consider things multiplied together to be part of a "term"

sly cape
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ok lets go to the exponents

twilit jetty
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oval uh

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that you still think addition needs to produce larger numbers is suspect

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we aint getting far if youre still thinking that

sly cape
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Thats the point

twilit jetty
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tell me

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why does addition need to produce larger numbers?

waxen musk
twilit jetty
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when I add on debt, I end up at a lower standing than I did before

lavish venture
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mtt i think hes being obtuse

twilit jetty
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this guy doesnt seem trolly enough to even do that

waxen musk
lavish venture
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idk man..

sly cape
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i have 5 apples how many do i need to bake the pie

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thats the meaning

lavish venture
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ive read through this conversation

sly cape
twilit jetty
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yes, its a long line of "Im trying to make a point but X, Y, Z get in the way"

lavish venture
twilit jetty
#

oval you can just agree that youre not comfortable with negative numbers

sly cape
lavish venture
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yep

twilit jetty
#

and that they make + and - signs do strange things

lavish venture
#

๐Ÿ‘

waxen musk
twilit jetty
#

knief is accusing you of deliberately being unclear to trip me up

sly cape
twilit jetty
#

you just dont agree with the language?

sly cape
twilit jetty
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well yes

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because this is very closely tied to the -x^2

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the main problem here is reading the symbols

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and you dont seem to agree with the usual way to do it

twilit jetty
sly cape
twilit jetty
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oval dont engage

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no progress will be made if you dont address the adding problem directly

waxen musk
twilit jetty
#

lets look at the broader picture here alr

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you just dont agree that addition can make smaller numbers, so when it does, theres always a reason why addition seemed to fail at its job

sly cape
twilit jetty
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for example, in -5 - -5,

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that would be addition to you, because -5 - -5 = -5 + 5 = 0, right?

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its ultimatley addition

sly cape
waxen musk
twilit jetty
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here a negative number made a number larger

sly cape
twilit jetty
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aha

sly cape
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in any equation

twilit jetty
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so what are we going to do with --5 then

sly cape
twilit jetty
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and what would it do?

sly cape
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subtract

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turn into more negative number

twilit jetty
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interesting idea

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now what would this number actually do?

sly cape
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i might find a thing/rule in mathematics

sly cape
twilit jetty
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thats the same mathematics that calls -2 + -1 adding though

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surely we can figure out what --5 is

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is it the same as 5? -5?

sly cape
twilit jetty
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ok I have an idea for you

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so far you agree that x + -x is always 0, right

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lets test it

sly cape
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okay

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yes

twilit jetty
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very suddenly changed your mind there

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in a way thats a good sign

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you doubted, tested, then confirmed

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we can do the same to see the nature of --5

twilit jetty
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since this should be true "for all x"

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now lets try this for x = -5, and we get:

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-5 + --5 = 0

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so whatever this --5 is, it must turn -5 to 0 by adding

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however, -5 + 5 = 0 also

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-5 + 5 = 0
-5 + --5 = 0

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does this convince you that 5 and --5 are the same?

sly cape
#

but double minus doesnt exist

twilit jetty
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suppose it does

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if it did exist, would it act like 5 in this example?

sly cape
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id say no as it would just result into being -5

twilit jetty
#

look closer at the place --5 is at in the expression

sly cape
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no wait

twilit jetty
#

-5 + 5 = 0

sly cape
#

-0

twilit jetty
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-5 + --5 = 0

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they are both numbers where, if you add it to -5, you will end up with 0

sly cape
#

okay -10

twilit jetty
#

oval, if you had x + -x = 0

fathom onyx
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-# I think the preliminary thing to learn here is whether -0 = 0 (which it does, but I'm not sure that's clear to Oval)

twilit jetty
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and x was -5

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then that means -5 + --5 = 0 too

sly cape
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but then the minus will just disappear

twilit jetty
#

wdym minus?

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stick to what we are accepting is true here

sly cape
#

--5

twilit jetty
#

so youd rather trust your feelings on this one?

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--5 shouldnt be 5, because the minuses both disappear?

sly cape
twilit jetty
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ever heard of a double negative?

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like here for example

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its a common idea

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not just in math

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--5 is an example of a double negative

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double negative things exist

sly cape
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that is smart

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but - * - = +

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but that is just +

twilit jetty
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and?

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so --5 is +5 then

sly cape
#

-5

twilit jetty
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-(-5 + 5) is -0

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not -5

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-5 + 5 is 0,

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so -(-5 + 5) is -0

sly cape
#

right -0

twilit jetty
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oval you need to be certain on your statements before you state them

sly cape
#

but that results into being undefinied so double negatives don't exist.

twilit jetty
#

yep

sly cape
#

-0 doesnt exist.

twilit jetty
#

that means we just need to figure out what -0 should be about

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well consider this

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0 + -0

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what would this be?

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and remember, x + -x = 0 is always true for any x

sly cape
#

-0

twilit jetty
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0 + -0 is -0, sure

twilit jetty
#

what do you get?

sly cape
#

-0

#

?

twilit jetty
#

x + -x = 0
0 + -0 = 0

sly cape
#

0 and then - 0

twilit jetty
#

so 0 + -0 is also 0 too

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that then must mean that 0 and -0 must be equal

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0 + -0 = 0 (from x + -x = 0)
0 + -0 = -0 (because adding 0 to anything doesnt change it)

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and so we have proven that 0 and -0 must be the same

sly cape
twilit jetty
#

now youre pulling out exceptions?

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its true that the kind of argument we're doing here would only really work for 0 and -0

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but its all we need to prove that 0 and -0 are equal

sly cape
#

cause one would be 0 + 0 = 0

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and the other one x + -x = 0 so x+ -0 = 0

twilit jetty
#

we're saying x is 0 in that case, so you have to replace the other x as well

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0 + -0 = 0

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we have that 0 + 0 = 0, and also 0 + -0 = 0 as well

sly cape
twilit jetty
#

in general, 0 and -0 are considered to be the same

sly cape
#

and whats the meaning behind this

twilit jetty
#

there is something important here

sly cape
twilit jetty
#

only in a pedantic sense

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when adding, multiplying them they are the same

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in the sense that there is nothing that can tell apart 0 and -0

sly cape
#

if i were to multiply it, one would result into a negative

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number

twilit jetty
#

not really

#

5 * -0 is 0

sly cape
#

still -0

twilit jetty
#

0 + -0 is 0, right

sly cape
twilit jetty
#

so 5 * (0 + -0) is 5 * 0, right

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since both numbers are equal, multiplying them by 5 must also be equal

sly cape
twilit jetty
#

then we distribute, this is something you agreed to

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5 * 0 + 5 * -0

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5 * 0 + 5 * -0 = 5 * 0 (distributing left side)

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yes?

sly cape
#

yes

twilit jetty
#

very good

#

then consider:

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5 * 0 + 0 = 5 * 0

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5 * 0 + 5 * -0 = 5 * 0

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in either case, 0 and 5 * -0 are both acting the same way in an addition sense

sly cape
#

mhm

twilit jetty
#

now we can confirm that 0 and 5 * -0 both act the same way in the multiplicative sense too

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you know -5 * 3 is the same as 5 * -3, right

sly cape
#

sure

twilit jetty
#

so similarly 5 * -0 is the same as -5 * 0

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and -5 * 0 is just 0 again, since anything * 0 is 0

sly cape
#

sure

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yeah

twilit jetty
#

and so -0 acts the same as 0 in both addition and multiplication

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and this is where the power of mathematics shows us something else interesting

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this is all we need to say that -0 and 0 are identical

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you see a lot of mathematics tries to assume as little information as possible

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to create the most "general" of results

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so a lot of mathematics has already been in the word to say that, for example,

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if x + y = x + z, then y = z

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and if xy = xz, then either y = z or x = 0

fathom onyx
#

-# I'd advise against introducing algebra like this at this moment tbh

twilit jetty
#

the guy already asked a question no normal person would ask

twilit jetty
#

I think theyre already in the mindset

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these arent exactly the rules that mathematics begins with, exactly, but its enough

sly cape
twilit jetty
#

now Im going to warn you

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this subject is called abstract algebra

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this is colleg-level math that attributes a lot of mathy things to seemingly very arbitrary, abstract ideas

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and at a lot of times, you cant predict the next direction a course is going to go when they teach you this

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why is this important, why remember that, what about those?

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the idea here is that with math at the advanced state that it is, these are important directions that get us farther in more efficient ways

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notice here: its not because theyre the most correct

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its just the most efficient, or the most commonly accepted, or at times just the easiest way

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most compromises in the name of more elegant mathmatics arent pretty

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to you, one of those is in how we view addition, and another one of those is in how we view -x^2

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see this line here?

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the basic structure that we have uses a set of things (for example numbers) and an operation that can combine them

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but not much more than that

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when we define addition, theres a reason why we define it as "5 + -3 is considered adding 5 + -3"

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youll notice here this structure has no concept of size

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what if, for example, we need to add 5:00 and -3:00?

sly cape
#

so what i said was actually right?

sly cape
twilit jetty
#

I dont see any exceptions here

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I see compromises against common sense, which as it turns out isnt very good at rigor

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suppose we need to add
...5555555555
- ...333333333

????????????

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as you can see, the usual notions of > and <, or > and <, break down

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we only have =

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and so why define addition with an extra > notion that we cant even have most the time?

twilit jetty
#

you said many things, most of them were not ideal, but a few are very good

sly cape
#

that when adding a negative number is subtractingg

twilit jetty
#

not a good idea

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we can say thats the case in terms of the symbols we use, sure, but beyond that no notion of > or <

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we can say x + -y is the same as x - y

waxen musk
twilit jetty
#

but thats about it, x - y doesnt have to be smaller than x

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you could have x + --5 and x - -5

fathom onyx
#

Well, "adding a negative number" isn't subtraction; a more appropriate phrasing would be
"adding a negative number is equivalent to subracting the positive number (that the negative number is the negative of)"

twilit jetty
fathom onyx
#

(This is not the same as saying that one thing IS the other; caution is needed there)

sly cape
#

and what they need

sly cape
twilit jetty
#

oval, I have to break it to you

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the mathematical definition of addition and subtraction doesnt align with the common real world use of addition and subtraction

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but as mathematics becomes more commonly taught,

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the mathematical definition is then a lot more common

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you know back then people couldnt even think of negative numbers, because it would mean to have less than nothing

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0 as a concept is relatively new in human history

fathom onyx
#

The "common" definition there doesn't by default take negative numbers as elements that can be used

sly cape
twilit jetty
#

its up there with the printing press and the car in "surprisingly recent inventions"

twilit jetty
#

you owe sheep, you owe land, you dont owe numbers

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what would it mean to even owe to a number? is 5 going to break down your house?

sly cape
#

you owe 2 sheep

twilit jetty
#

doesnt mean you "have -2 sheep"

sly cape
#

which - translate to not have

twilit jetty
#

it just means you need 2 sheep

fathom onyx
#

Taking "owing" something as literally a negative of "owning" something is a relatively new concept

sly cape
#

youre on minus balance

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just like a bank account

fathom onyx
#

Credit/debit book-balancing doesn't even rely on negative numbers, though

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Again, it bends over backwards to avoid them

twilit jetty
#

you know people used to attempt to solve ax^2 + bx + c = 0

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but without negative numbers,

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they came up with like 17 different variants of the equations, all only using positive numbers

fathom onyx
twilit jetty
#

so instead of solving x^2 - x + 4 = 0,

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theyd solve x^2 + 4 = x

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and negative numbers would be removed out of it

twilit jetty
# sly cape when?

I dont exactly remember my math history, but its around the medieval ages or the enlightenment

fathom onyx
# sly cape when?

Literally up until the 16th century was what mtt saying the normal approach

twilit jetty
#

it predates the quadratic formula

sly cape
#

so negative numbers didnt exist?

twilit jetty
#

they existed to no one, because they couldnt conceive of them

fathom onyx
#

That's literally what he's been trying to tell you

twilit jetty
#

up until now, where we can define negative numbers

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and in doing so, we also must redefine addition and subtraction

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addition means to mix, subtraction means to negate the second number then mix

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--4 = 4

waxen musk
twilit jetty
#

and -0 = 0

sly cape
#

So you said that people couldnt for example remove 1 sheep from 2 sheep?

twilit jetty
#

youd just get 1 sheep oval, say that slightly differently

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they cant remove 2 sheep from 1 sheep

fathom onyx
#

Heck, the fokken EQUALs sign wasn't even commonplace until the 1500s

twilit jetty
#

because you only have the 1 sheep

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consider this, the idea behind negative numbers is common, but the idea of a negative number is recent

burnt flame
#

this is still going

twilit jetty
#

if you had 5 apples, and you needed 7,

twilit jetty
#

youd think "Im going to take 5 apples and I still need 2 more"

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youre not going to think "I currently have negative 2 apples"

fathom onyx
# sly cape "=" replaced *equals to*

and the reason it even exists at all was because one guy decided to express that two things were equal by representing them as two incredibly long lines that were of equal length

twilit jetty
#

so in short,

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mathematics didnt get here through arbitrary rules

fathom onyx
#

Like, this was from 1557

sly cape
twilit jetty
#

oh sorry, let me elaborate

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if you had 5 apples, and you needed to give someone 7 apples,

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youd think "Im going to give 5 apples and I still need 2 more"

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that was a major typo, I dont know how that got mixed up

stone ivy
#

@sly cape bro what is this thread about at this point?

twilit jetty
#

oval doesnt think 5 + -4 should be called addition because you end up subtracting to get a smaller result

sly cape
#

Or well the truth

twilit jetty
#

"some people" being the math community

waxen musk
fathom onyx
#

Your theory's demonstrably wrong, is what people are trying to get at

stone ivy
fathom onyx
#

Or at the least, subpar

twilit jetty
#

Id say its inefficient

sly cape
twilit jetty
#

its more suitable for modern math today to change + and - to what they are

waxen musk
sly cape
#

But a correct way to express that

fathom onyx
#

A game the-

sly cape
#

I'm probably not only one who thinks that

stone ivy
#

bro are you guys discussing history or philosophy or somethin'? Cuz this ain't any maths.

waxen musk
twilit jetty
#

to date, you are the only person who thinks that we need to make addition and subtraction great again

fathom onyx
sly cape
#

@stone ivy I just wanted to know the difference between multiplying (-2) or without brackets

twilit jetty
#

no you dont

#

you also think 5 + -4 is subtraction

sly cape
#

I gave example at the beginning.

twilit jetty
#

you said -x^2 should be viewed as (-x)^2

sly cape
twilit jetty
#

so -5^2 should be -5 * -5

twilit jetty
sly cape
#

Subtracted.

twilit jetty
#

yep

#

addition isnt being real there

sly cape
#

Yea so now you agree?

twilit jetty
#

even though theres a + sign

sly cape
twilit jetty
#

bro thats a common thing people do where they repeat your point to make sure they got it right

#

Im repeating it to make sure I got what you said right, doesnt mean I agree with it

stone ivy
#

that's a hard word to pronounce.

twilit jetty
#

meta-mathematics

#

you can pronounce it like that

sly cape
#

So this is a subtraction.

5 + -4

waxen musk
sly cape
#

@twilit jetty

twilit jetty
#

we dont call it that

#

we call it adding a negative number

#

which ends up as subtracting a positive number

#

thats because you used a + sign, that is all

fathom onyx
twilit jetty
#

5 add -4 means 5 + -4

sly cape
twilit jetty
#

theres ideas in there I think about ZFC, the minimum amount of rules you need to build most of mathematics

twilit jetty
#

do we really have to use two different kinds of names?

stone ivy
twilit jetty
#

one for when -2 + x gets bigger, one for when -2 + x gets smaller?

twilit jetty
twilit jetty
#

and what are we going to call the + sign then?

sly cape
#

As it is more precise.

sly cape
twilit jetty
#

no really

#

how do you write -2 + x into words then

#

and remember, this whole time in history

#

our progress has been in making math easier to read and speak

sly cape
#

sum of -2 and x

twilit jetty
#

doesnt sum mean add

#

youre going to just defer to the word sum now?

sly cape
twilit jetty
#

x can be negative oval

sly cape
#

so -2 will just go greater

sly cape
twilit jetty
#

x can be -5 you know

#

doesnt have to have a - sign before it

#

the letter x doesnt only stand in for positive numbers

fathom onyx
#

x just stands for "a number" here at this point

#

Without any concern for whether it is positive, negative or zero

sly cape
#

Yea so it an addition up until the unknown is known

fathom onyx
#

(I think another thing that has to be explained is that zero is specifically neither positive or negative)

twilit jetty
#

repeat that sentence to make more sense too

#

if we dont know whether x is positive or negative,

#

what would you call -2 + x, in words?

#

write it out in full for me

fathom onyx
#

And bear in mind you can't use "sum", because that defaults to addition, and as per your words this can't always be an addition

sly cape
twilit jetty
#

the full thing please

sly cape
#

What fulll thing?

twilit jetty
#

if x is negative, you couldnt call -2 + x an addition because then you end up subtracting

#

if x is negative, what would -2 + x be called then instead

fathom onyx
# sly cape What fulll thing?

You're answering the question

if we dont know whether x is positive or negative,
what would you call -2 + x, in words?
as a full sentence

#

Meaning you need the "if..." part as well

sly cape
#

Until x is known

twilit jetty
#

oval, that only works in elementary school

fathom onyx
#

Okay, there's another concept you seem to be confused with

#

"undefined" has a definition, ironic though this sounds

twilit jetty
#

as we get into higher math, we do need x to be general like this

#

we need a name

#

a description

#

what are we going to call -2 + x?

sly cape
#

Well I can call this adding and then changing the unkown to a numer which then results into subtracting (if so)

twilit jetty
#

oval, I hope you understand,

#

thats a long-ass name

fathom onyx
#

But IF WE DO NOT KNOW WHAT x IS, this is useless

twilit jetty
#

and thats why we just use the word "plus"

#

thats the reason why addition does what it does

#

we consider addition and plus to be a shorthand for +

sly cape
fathom onyx
#

Just because you don't know what this is equal to, doesn't mean you can call this "undefined"

sly cape
#

Or Unfinished equation

fathom onyx
#

That's not what the word means

#

You can't call it that either

#

Because that implies this is TO BE an equation

#

There's nothing here that suggests that it SHOULD be one

sly cape
#

-2 + x this tell us what?

#

Nothing

#

if we dont know the x

twilit jetty
#

this tells us an expression that needs to do the operation of addition on -2 and x

#

oval,

#

-2 + x actually does mean something

#

it has a picture, for example

fathom onyx
#

This tells us we have SOME QUANTITY x, and we're +ing the number -2 to it

sly cape
twilit jetty
#

which looks like this

twilit jetty
fathom onyx
twilit jetty
#

math only exists to be solved?

sly cape
twilit jetty
#

you say that kind of talk with anything else and youre going to look insane

#

but for math, everything is only to be solved?

#

I just want a noun man

#

something to call -2 + x

#

and until then, we're just going to call it "-2 plus x"

#

because its short and its simple

waxen musk
sly cape
brittle grotto
#

wow. how has such a long conversation sprung from a minor notational question

twilit jetty
#

youve never done your taxes before?

#

social security?

#

how are those written?

sly cape
#

Are you making me dumb?

twilit jetty
#

(gross income) * something, thats for sure

#

theres an expression for you

sly cape
#

But youre now saying that math doesnt need to be solved

twilit jetty
#

you went further

sly cape
#

okay then you won't know the answer

twilit jetty
#

now youre saying theres no point in making any expressions

twilit jetty
#

if the tax is 8.75% in your state, that means you do (current price) * 1.0875 to get how much it costs after tax

#

theres purpose in formulas

#

Id like to know how much I need to pay for something, and thats (current price) * 1.0875

#

how do we use it? we can use it for more than just one price, for example 19.99 * 1.0875

#

we can use it for any price in the region we are in

twilit jetty
#

what you lose in being specific, you gain in being general

sly cape
#

Okay but you said that some mathematics equation should be left out without a solution or something like that

twilit jetty
#

this is the nature of math, it says how things can be like in general

twilit jetty
#

if you wanted to, for example find how much $99.99 costs after tax,

#

and I told you to do that

sly cape
twilit jetty
#

oval listen to me

twilit jetty
#

(current price) * 1.0875 by itself isnt a solution to a specific problem

#

its only a solution to a general problem of "how do I calculate the price after tax?"

sly cape
#

exactly

twilit jetty
#

if I had $99.99 * 1.0875, that can answer "how do I calculate the cost of a $99.99 product after tax?"

#

but it cant answer "now what about this $74.99 product?"

#

(current price) * 1.0875 and $99.99 * 1.0875 are only solutions to their kinds of problems

#

one for the general, one for the specific

#

and youre thinking "only the specific ones matter"

twilit jetty
#

-2 + 5, but never -2 + x

sly cape
#

THere's a difference between knowing how to calculate and how to do it

fathom onyx
#

"how can I hammer a variety of nails into this wall?"
"fuxk me idk, hammers are undefined"

#

This is not far off from how your train of logic reads

#

Related question - you do know the difference between an equation and an expression, right?

twilit jetty
sly cape
twilit jetty
#

put it this way

#

we have a description for -2 + 5

#

"negative two plus five"

#

"adding negative two and five"

#

these are examples

fathom onyx
#

The POINT is that, "current price" is our unknown variable

twilit jetty
#

but lets say we need to represent adding -2 to something in general

#

now naturally youre not going to be happy with the word adding...

#

because that something could be my debt, which is negative

#

so what would our description of -2 + x be?

sly cape
twilit jetty
#

now heres something I dont think youre familiar with

#

we in fact can do things with -2 + x

#

its true that we do not know what -2 + x's value ever is

#

given we dont know x's value

#

but that doesnt stop us from doing math on -2 + x itself

sly cape
#

oh i know where you going

twilit jetty
#

so if we need to do math on -2 + x itself,

#

we need a noun for it

#

and is "unsolvable subject" really going to tell someone what youre seeing on the screen?

sly cape
#

youre just talking about basic algebraic equation?

twilit jetty
#

you can afford more words than that

stone ivy
#

This thread is truly getting ridiculous.

twilit jetty
#

so no, Im not

#

for example, the slope of -2 + x is 1

#

thats an example that doesnt use an equation

sly cape
fathom onyx
#

(which is why I'd asked whether you knew the difference between "equation" and "expression", because you keep using one term to mean the other)

twilit jetty
sly cape
#

but you guys misinformed me in the first place

twilit jetty
#

you misconstrued us

#

I dont believe youre the perfect arbiter of the english language

sly cape
#

you said that those were two different things

twilit jetty
#

its possible that, just maybe, you misread something out of the very complex idea on display here?

twilit jetty
#

different names for the same things

sly cape
sly cape
#

the order was different

fathom onyx
#

Fuxk me, "words have definitions" should not have to be a concept that needs explaining sad

#

But it's getting to that point

twilit jetty
#

it means B, O, DM, AS

sly cape
#

why would be everything be in order but division and multiplication

twilit jetty
#

it doesnt mean B then O then D then M then A then S

twilit jetty
sly cape
#

Yea and they flipped

twilit jetty
#

yep

sly cape
#

one had DM other MD

twilit jetty
#

and what are you going to do about it?

#

we cant do anything about it

sly cape
#

yeah so you misinformed me that those were different things

sly cape
twilit jetty
#

those were different names oval

#

yea because you mentioned them first when I entered the conversation

sly cape
twilit jetty
#

you mentioned both BODMAS and PEMDAS in the same message

fathom onyx
#

@sly cape No he didn't misinform you; you didn't read what he said

twilit jetty
#

an independent third party here looking over the messages and confirming that, yes, theres more meaning to the differences than just the word "different"

#

you know not everything can fit into one message, they need elaboration

slate ferry
#

3(-2) looks a lot better than 3 -2 which could be interperted incorrectly

sly cape
twilit jetty
#

and the concept I elaborated on is exactly the same concept I am telling you now

fathom onyx
#

But since you've been confusing + and -, he's had to take it into a more elementary situation to explain things before you even consider the order of operations

twilit jetty
#

theres a distinct lack of care here, you dont care about any of this

#

you just think youre right without ever hearing the other side out

sly cape
fathom onyx
#

So don't think he's diverting the conversation; you're missing, and more importantly displaying a lack of, a crucial understanding

twilit jetty
#

its a fault of a lack of care, that you just want this one question answered and not realizing how far up you need to climb

#

this is a flat earther asking "how do I explain the motion of the moon?" then being surprised when we have to explain the heliocentric model

sly cape
waxen musk
#

@sly cape what is your question at this point? is it still on the 3(-2) notation?

twilit jetty
#

please understand: you are stating a dangerous precedent

#

we can show you how mathematics commonly answers these questions, so that you can learn their language

#

we cant fix the typos in the words we see, we cant remove the silent letters

#

but we can tell you how it works so you can get used to it

#

you dont have to agree, I often times dont, but you have to use the words

fathom onyx
#

But if you're going to misunderstand - and misuse - their language from the outset, you're going to keep slipping on banana peel after banana peel

sly cape
slate ferry
sly cape
slate ferry
#

again, i must state, there is a language barrier between oval and us!

#

maybe this is jut a big misunderstnading

twilit jetty
#

just like the flat earther here

twilit jetty
#

that is why we are giving you more material to show you that theres a damn good reason we do things this way and not the other way

#

I couldnt even finish telling you that in both examples

waxen musk
twilit jetty
#

the addition and the ^ thing

#

if you do not want to be convinced, there is nothing we can do to help you

waxen musk
sly cape
twilit jetty
#

times up for me, I gtg

waxen musk
sly cape
#

There are many factors to this

slate ferry
sly cape
#

i have lower

waxen musk
#

oh ok

slate ferry
sly cape
slate ferry
#

ok listen dear, do you have any more concerns

waxen musk
#

so, lets adjust to get back on the topic of your question

sly cape
#

I stayed up til 3 am for this..

#

And we're just gonna leave it unsolved

#

Oh wow he left..

slate ferry
#

we'\re here

#

hellooo

waxen musk
#

are you still having issues with the difference between (-x)^2 and -(x)^2

sly cape
#

Yes

brittle grotto
#

ok can I just put in my two cents

#

math notation is meant to be as clear as possible

#

generally, it's not worth obsessing over some divinely correct interpretation of an expression

waxen musk
#

so, concretely, when we say
(-x)^2, by definition, we mean (-x)^2 = (-x)*(-x)
-(x)^2, by definition, we mean -(x)^2 = -(x)*(x)
does this distinction make sense to you @sly cape ?

sly cape
olive matrix
#

hey so just a reminder to everyone here that you are always free to leave this conversation at any point if it's making you upset or angry

slate ferry
sly cape
#

The whole discussion was (maybe not the beginning cause it was about pedmas )

brittle grotto
#

here's the thing

#

we generally read -x^2 as equivalent to -(x)^2

#

and this is a well-established convention

sly cape
brittle grotto
#

so I guess... my question is... are you expressing a personal distaste of this convention?

sly cape
#

okay so

-x^2 is -x * -x

brittle grotto
#

welll... I would not write it like that

#

it may be more clear to write it like (-x)*(-x)

waxen musk
sly cape
#

I think mtt even said that

#

nvm only one -x

waxen musk
brittle grotto
#

the righthand expression you wrote might be seen as a little unclear, oval

waxen musk
brittle grotto
sly cape
#

Okay so lets start from beginning

waxen musk
sly cape
#

-x^2 = -x * x

waxen musk
#

yes

sly cape
#

and then -(x)^2

waxen musk
sly cape
waxen musk
#

yes

#

in both cases, we want to do ^2 to the x first

sly cape
#

so its -(x) * -(x)

waxen musk
#

you brought a stray - sign

#

all were saying with the parentheses in -(x)^2 is that we want to do ^2 to x first, we are not doing - to x first

#

does that make sense to you?

sly cape
#

oh yeah so x * x and we bring the minus?

waxen musk
#

yeah

#

now what about (-x)^2

sly cape
#

and with (-x)^2 do we copy twice the minus?

waxen musk
#

yup

sly cape
#

thats soo easy

waxen musk
#

so, now you are absolutely clear on the difference between (-x)^2 and -(x)^2 and -x^2?

sly cape
#

-x^2 = -x * x
-(x^2) = -x * x
(-x)^2 = -x * -x

waxen musk
#

good

#

now, do you have any further questions? or does everything make sense to you

sly cape
#

i think its okayyy

#

but idk if i should close

waxen musk
sly cape
#

also i have one question

waxen musk
#

but otherwise, if you dont want to, you can close

#

yeah, go for it

sly cape
#

do you know SYSTEMS OF EQUATIONS?

waxen musk
#

yeah

sly cape
#

How to do this using the substitution method? We don't have a single algebraic letter..

waxen musk
#

so, this is telling us to solve for when both equations are true
take one equation, doesnt matter

#

lets start with the 2x+3y=8

#

solve for one of the variables

#

lets say x

#

how do you rewrite 2x+3y=8, but as x=...

waxen musk
sly cape
#

3x = 8 -3y

waxen musk
#

2x = 8 - 3y

sly cape
#

ik that but i want to have 1x

#

sorry

#

2x

waxen musk
#

its okay

halcyon vale
waxen musk
#

i can divide both sides by anything but 0

#

what should i divide 2x by to make it simply x

sly cape
#

maybe divide the other side with 2x too

waxen musk
#

that would just give us 1

halcyon vale
sly cape
#

(8-3y)/2x

waxen musk
#

we still want the x here

#

but youre close

sly cape
#

but with 2

#

not 2x

waxen musk
#

mhm

sly cape
#

(8-3y)/2

waxen musk
#

yep

sly cape
#

thats easy

waxen musk
#

we can simplify this, itll make it easier

#

how do i simplify (8 - 3y)/2

sly cape
#

it will be

#

4-3y

waxen musk
#

you got the 4 part right, but you lost the /2 on the 3 part

#

you have to divide both numbers by 2

sly cape
#

yeah which is 4-3y/1

#

= 4-3y

halcyon vale
waxen musk
#

now, youll be saying 3/2 = 3/1 if you do that

halcyon vale
#

what is your thought process behind dividing 3y by 1?

slate ferry
# waxen musk how do i simplify (8 - 3y)/2

brackets here are important! you see, its asking you to divide the whole thing by 2, n ot just 8 or not just 3y... you need to divide the both of them by 2 which is indicated by the brackets

sly cape
#

$\frac{8 - 3y}{2}$

grand pondBOT
#

TrulyOval

waxen musk
#

yes

slate ferry
waxen musk
#

now how do we continue from here

sly cape
#

its easy to divide 8 and 2

waxen musk
#

good

sly cape
#

and 2 : 2 is 1

#

so it will just be 4-3y

waxen musk
#

what do you mean 2:2 is 1 here?

sly cape
#

divided

#

2 and 2

waxen musk
#

thats a ratio, which is slightly different than a fraction first of all

sly cape
#

well thats how i mark division

waxen musk
#

but yes, 2/2 = 1, but we actually have 3/2 here

#

how did you arrive at 2:2?

sly cape
#

wait

#

i have an idea

waxen musk
#

hm?

sly cape
#

$2(8-3y)$

grand pondBOT
#

TrulyOval

waxen musk
#

we cannot say x = 2(8-3y)

sly cape
#

why? i eliminated denominator

slate ferry
waxen musk
#

because thats exactly saying $\frac{x}{2}=8-3y$ and $\frac{x}{2}\neq 2x$

sly cape
#

well multiplied

grand pondBOT
#

Cycadellic

waxen musk
#

dividng 2 was the correct step here

#

we now need to simplify $x=\frac{8+3y}{2}$

grand pondBOT
#

Cycadellic

sly cape
#

1/2 * 2 = 1 so its solved

waxen musk
#

where is this *2 coming from?

sly cape
#

from denominator

waxen musk
#

what do you mean from denominator?

slate ferry
sly cape
halcyon vale
#

what if we just dont simplify it? x gets multiplied by 4 in the second equation so theres no need to simplify this expression

waxen musk
waxen musk
sly cape
#

yeah

waxen musk
#

i see them bring a *2, so thats a clear point of confusion which must be hammered out

sly cape
#

i get it

#

now

waxen musk
#

so what do we have?

#

x=...?

waxen musk
#

so, we have this rule

#

$$\frac{a+b}{c}=\frac{a}{c}+\frac{b}{c}$$ for any possible $a,b,c$ except $c\neq0$ because we cant divide by 0

halcyon vale
#

\frac{\left(a+b\right)}{c}=\frac{a}{c}+\frac{b}{c}

grand pondBOT
#

Cycadellic

waxen musk
#

oh woops

sly cape
#

right

waxen musk
#

its (8-3y)/2 lol not +

#

but yes, the rule still applies

#

so, $$x=\frac{8-3y}{2}$$

grand pondBOT
#

Cycadellic

waxen musk
#

where to go from here

sly cape
#

\frac{4}{1} + \frac{3y}{2}

#

$\frac{4}{1} + \frac{3y}{2}$

grand pondBOT
#

TrulyOval

waxen musk
#

correct

sly cape
#

yayayayay

waxen musk
#

do -

#

i accidentally said +

waxen musk
#

its actually -

sly cape
#

$\frac{4}{1} - \frac{3y}{2}$

waxen musk
#

great

#

now for the substitution

grand pondBOT
#

TrulyOval

stone ivy
#

guys just stop. get some help.

waxen musk
#

$$x=4-\frac{3}{2}y$$

grand pondBOT
#

Cycadellic

waxen musk
#

we substitute this into $4x+5y=15$

grand pondBOT
#

Cycadellic

waxen musk
#

do you know how?

sly cape
#

ik

scenic wyvern
slate ferry
sly cape
#

$4\left(\frac{4}{1} + \frac{3y}{2}\right) + 5y = 15$

grand pondBOT
#

TrulyOval

slate ferry
#

YEAH

#

GOODJOB

waxen musk
#

now, do you know what to do from here?

sly cape
#

yea yea

#

$\frac{16}{1} + \frac{12y}{2} + 5y = 15$

grand pondBOT
#

TrulyOval

waxen musk
#

good, now, what do i do about the y?

slate ferry
#

YES! GO BRACKETS WORK GO

stone ivy
#

$y = \frac{-1}{11}$

slate ferry
#

?

#

!nosols

midnight plankBOT
#

As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.

slate ferry
#

wait its wrong lmao

waxen musk
#

also, not quite

slate ferry
#

still

stone ivy
sly cape
#

16 + 6y + 5y = 15

slate ferry
waxen musk
slate ferry
#

what is this person doing

waxen musk
#

idk

sly cape
#

16 - 15 = -11y

waxen musk
#

yes

#

lol

grand pondBOT
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fort craft ๐Ÿ‡ต๐Ÿ‡ธ

scenic wyvern
midnight plankBOT
# stone ivy $y = \frac{-1}{11}$

As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.

scenic wyvern
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let the helpee try it themselves

waxen musk
stone ivy
waxen musk
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whats 16-15

sly cape
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-11y = 1

slate ferry
sly cape
waxen musk
stone ivy
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@scenic wyvern@slate ferry sure. I won't.

slate ferry
slate ferry
sly cape