Can anyone explain this to me

[keen sentinel]

lol its you again

[worldly creek]

lmfao ye

practising a bit

[short marlin]

$$\dfrac{x}{1-x} -4x = \dfrac{x-4x(1-x)}{1-x}=\dfrac{x-4x+4x^2}{1-x}=\dfrac{4x^2-3x}{1-x}=\dfrac{x(4x-3)}{1-x}$$

[pallid wasp]

Lurtz

[keen sentinel]

how does working this out even like work 😭

what did yall even do

[worldly creek]

so u have that -4x is out of the denominaor of the fraction

ill send a pic again

[short marlin]

Basically you say that $\dfrac{1-x}{1-x}=1$ and you multiply by it. (If $x\neq 1$)

[worldly creek]

u can see that they have different denominators

to plug in the -4x in the other fraction u have to multiply -4x by the denominator

like this

[pallid wasp]

Lurtz

[worldly creek]

and the denominator -4x had in the beginning was 1

[worldly creek]

like this

ps to add a number to a fraction they have to have the same denominator

its the part under the line of the fraction

in this case 1-x

[keen sentinel]

I understand what you did here

but

how do we end up with 1-x twice guys?

[worldly creek]

lemme see again

so u have to have a common denominayor to add the two fractionsù

in this case u have to use 1-x bc its common to both

since -4x has as denominator 1

[short marlin]

It's above you, salt! 😀

[worldly creek]

so u have to find a way to make -4x have as denominator 1-x

as a whole

so

u can think it like this

u can multiplie -4x with 1 since it apparently doesnt chnge anything

but u can write 1 as a fraction however u want

bc 4/4 is 1, 8/8 is 1, 4x/4x iss 1

and also 1-x/1-x is 1

ill send a pic

now u have the same denominator

as x/1-x

and u can add them

if u dont get something tell me

[keen sentinel]

I was looking at it and watching lurtz and your explanations and it actually makes sense now

[worldly creek]

good!

[keen sentinel]

hmm

distance and speed

what do I do for these type of questions

[worldly creek]

so this is physics

u need to use he formulas

let me see

ok i think i got it

i'll rewrite it cause its messy

[worldly creek]

The circled one are formulas

And the one in the squarw is the answer

It should be correct

Its an approximation

[keen sentinel]

ah alright

@worldly creek

you remember

how woe did the

1-X equation right

how do I make this one = to 0

[worldly creek]

ok

just give me a sec

im doing another problem

[keen sentinel]

oki

[worldly creek]

ok im back

illl do it

its the equation written with the pen

so basically

the question is asking to find which value of x makes the equation 0

[sly lintel]

Btw be careful to acknowledge when the function is not defined.

[worldly creek]

and as u can see we have found 3 values for that

[worldly creek]

oh gosh ur right!!

i totally forgot

[keen sentinel]

what does that mean

[worldly creek]

x ≠ 1

so two values

[worldly creek]

basically a fraction cant have 0 as denominator

cause it makes it impossible to solve

[keen sentinel]

oh

[worldly creek]

0 can only be on the numerator

ill resend the pic

forget the pic i sent

ill send another one

[sly lintel]

And so if you get x=1 as a solution you just cross it out(that is not this case but keep it in mind always)

[keen sentinel]

alright

[sly lintel]

But always check if the function is defined

[worldly creek]

to do so u have to put the whole denominaor ≠ 0

[sly lintel]

You should check out khan academy they have great resources on this topic. Just practice a lot and remember, math is never hard it just takes a lot of time!!!

[keen sentinel]

how did lurtz do that with the bot ?

[worldly creek]

agreed its rlly good to learn maths!!

[keen sentinel]

Ill do that

[worldly creek]

so going on

after u have checked if the function is defined

u hav to find the possibles values of x that make the equation 0

so u solve it until step 4 (in the image)

where u have only one fraction

then u put only the numerator equal to 0

and solve for x

is there something u didnt understand?

[keen sentinel]

so you have to always plot the 1-x into the start

of the equation?

[worldly creek]

yes

to make the fraction one

i mean to have only one fraction

[sly lintel]

@keen sentinel for which value a will this expression be undefined(it’s not an expression technically speaking)

[keen sentinel]

is the undefined one a+1 and the defined one a+2

[sly lintel]

Let me rephrase it

For which value a will denominator be equal to zero

[keen sentinel]

a=-2

[sly lintel]

Great

So the expression is undefined for a=-2

You can’t divide by zero

[keen sentinel]

yea

[sly lintel]

That’s it you got it man 😊

Always check for that

And write it out

[keen sentinel]

thank yall

so much fr

[sly lintel]

Just remember to check out khan academy. It’s free and it has great explanations and exercises, with it all of high school maths will be much easier 😎

[keen sentinel]

whats the thing you put at the side of the x=0

[keen sentinel]

can you tell me some topics I need to look for in there

[worldly creek]

what fo u mean

[sly lintel]

What class are you in right now

[keen sentinel]

The weird bracket

[worldly creek]

hahaha its an arrow

to show there are two different results

cause when u have a moltiplication that has to be equal to 0

at least one of the different factors has to be 0

so if they both have an x

u evaluate both

separetly

[keen sentinel]

I get 11th grade work

[worldly creek]

how old is 11th grade

i mean the students

16?

[keen sentinel]

16

[keen sentinel]

Yeah

[worldly creek]

OOP I GOT IT

[keen sentinel]

Lol

[worldly creek]

what class are u taking?

[sly lintel]

I am not an American so I don’t really know what that means xd

What is the current topic you guys are going over in class?

[keen sentinel]

Stuff like quadratic equations, simplifying, graphs

Factorization

[worldly creek]

i think thats normal at the beginning of the year as a 16 year old

[keen sentinel]

I gotta write csec

😭🙏🏾

[sly lintel]

Check out Algebra 1 course on khan academy

Basically just start at the beginning and grind when you have free time.

You really need to drill in the basics. If you do calc will be easy.

[keen sentinel]

I'll do that tomorrow fr

Can you guys can make like a group chat if that's ok with yall

[sly lintel]

I am sorry man, but I am really busy.

[keen sentinel]

Ah

[worldly creek]

ill befriend u

oh wait we already did that

[keen sentinel]

Ye

[worldly creek]

well im still on holiday for a while

u can dm me when u need help

[keen sentinel]

Alright thanks