#formula for this?
718 messages · Page 1 of 1 (latest)
Doesn't seem like there's an obvious (workable) pattern, so I would suggest solving for x in terms of a, then substituting in the second formula.
ohh ok
!nosols
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.
my bad
but yes exactly this, there isnt a clear relationship between the two you kind of have to play around with the equations
yeahh hpw do solve for x
im not sure you need to, i think it just wants an expression for the second equation in terms of a
huh so wdid
if you mean how to find an equation for x in terms of a, like Fern mentioned you want to find a way to substitute the first equation into the second (solve for x in terms of a), e.g
finding the square of both a and x, and using that
or
finding the reciprocal of both sides of the first equation and using that
etc.
is it this
$x^4+3x^2+1$ is distinctly not equal to $(x^2+3x+1)^2$
A miscellaneous Fern
I would suggest taking $x = a(x^2+3x+1)$, rewriting it as a quadratic equation, and solving for x
A miscellaneous Fern
$AX^2+BX+C = 0$
A miscellaneous Fern
Oh really
Huh.
Well in that case you can still take the equality x = a(x^2+3x+1) and get some work done with it.
@subtle geode Had good ideas for manipulations
is my everything at left side correct?
Yes, the left side is fine
is it possible to make x^2 from left side equal to x^4+3x^2+1
idkkk how manipulations can help w it
like
i cant see any other form
i suggest you learn it
self learn? ehhh i need notes then
just divide the numerator and the denominator by x and in the second equation by x square, after that you will see that x+3+1/x =1/a and by raising it to the send power you will get the the second equation’s denominator.
then
first equation:
x+3+1/x = 1/a
wait what
do i power the 1/a ?
PLEASE TELL ME IM RIGHT
almost right but it will be 6 not 3 then since (a+b) square is a square + b square +2ab and this 2ab part becomes 6 since 2•3•x•1/x is 6. now let’s say the second equation equals b. Thus 1/b = x2+3+1/x2 if we divide numerator and denominator by x2 .
yeah
lets just say ik the (a+b)^2 formula but i dont rly understand the concept im just memorizing it lol
you dont understand the binomial formular? 😔
you can’t remember(a+b)^2 formula? u just need to practice with it a lot.
no i mean
i remember it
but i dont know the concept
like im just memorizing it dumbly
so thats why idk how to apply formula in questions
whatever that is... i call it algebra formula
I know the best way to understand it intuitively.
please
i
that’s the way I learned it
lol yeah that’s might be complicated if you are not good at geometry.
if i do it in algebra way, (a+b)^2 = (a+b)(a+b) right
which is
a^2b+ab^2
isnt it
yeah that’s a good way to understand it
how did you get that?
like how can it become a^2 + 2ab +b^2
cuz like
a(a+b) = a^2b
then the second part
b(a+b) = ab^2
and add
together
= that
(a+b)(a+b)=a(a+b)+b(a+b)=a2+ab+b2+ab
that’s not correct
4(a+b)=4a+4b isn’t it?
YES YES
😂
so you struggle with when to use this formula right?
yeah
not just that
every formula
like if its not direct idk what formula to use
you just need to do a lot of practice , just find a book with similar similar problems and do them daily. It’s the only way to understand it.
i have a lot alot alot more questions like this
that idek how to do
I guided you a way to solve your question. Try another approach and decide which one is more suitable for you.
wait wheres the (a+b)^2 thing in this question
aren’t they about the same topic?
kinda but theres even more formulas
like its a topic where we learn a bunch of formulas
and questions whereu might need to mix formulas
but once again i dont understand the formulas and is just memorizing them
you don’t need to understand the formulas. You can prove them based on easy steps. However you don’t need it now. You just need to learn how to apply them correctly. Just memorize them for now. Focus in the problems
but some of the questions r too random like i dont see the formula
this for example and the formulas i learnt are
then ask me and I will guide you or your teacher
oh that seems funny!!! let’s say that this expression is equals to x then multiply both sides by (2-1)
why 2-1
because (2-1)(2+1)=(2^2-1)
then (2^2-1)(2^2+1)=(2^4-1)
and so on until we reach the last one
sooo keep doing it?
basically our goal is make from large expression a smaller one. and the best way to do that is applying (a-b)(a+b)=a2-b2 !!!
yep… and after few times you will understand how it will end
wait let me attempt doing it in the dumb way first
every time you just get (2 in the twice bigger power -1)
waste of time. but You can do that if you want
wait but it's supposed to be 2^2+1 not -1
ah then nvm
but once again i dont see the formula
wheres a and where b
why? isn’t the formula (a+b)(a-b)=a2-b2??? not a2+b2
I agree those questions aren’t for beginners in this topic.
year8
oh so the -1
isnt referring to the question
cuz the question is (2^2+1)
but the formula shows -1 right
OH
NVM
I GET IT
-1^2 = +1
right
THANK gods
yeah

wait so this
yes?
but how can i multiply the long ahh expression by (2-1)
dont i have to do it one by one then
cuz idk whats in between
i mean i know
you don’t need to write the whole equation, we’re looking at one part of it.
right so i only multiply the part i can see with (2-1)
the first part (2-1)(2+1) become (2^2-1) then we multiply it with other guy next to him and so on… just try it few times and you will get it
ehh okay wait il ltry first
use this (2^2-1) to multiply w other or
(2-1) to multiply
(2-1) has dissapeared already with 2+1
or that
2-1 * 2+1=2^2-1
huh
it's not -1 it's 1
waitttt
yeah
is that clear to you? 100%?
it's not -1!!!! you should raise 1 to the power of two and then add - there
yk im taught that the term comes with the minus symbol is that true
thats messing with my mind rn
but doesnt the minus symbol always come with the term b (aka 1)
so -b / -1 same thing
then -1^2 = 1
NOOO!!!
minus doesn't has anything to do with b
oh wadafak my teacher always teach the symbol b4 the term is like togther
I think you just misunderstood her or sth....I hope the part with why (x-1)(x+1)=x^2 - 1 is clear
😭 pls
lemme make it clear it's :( (a^2)-(b^2) ) minus seperated from b^2!!!
OKAY OKAY SO THE 1 DONT HAVE ^2 BECAUSE 1 X 1 = 1?
it's not a^2 (-b^2) no!!!
yESSS you can write 1^2 if you want but 1 in any power(rational) is always 1!!!
okay okay i understan
yaaay
ill just have to ignore what my teacher said about the -b and -1 shit
oh wait i kept thinking its ^6, ^8, ^10 after the ^4
like the ...
huh the last one is 2^2^10 which is 2^1024 (i used calculate to cheat ;-;)
the power sequence is add 2?
or multiply 2
multiply
and i need another tutorial on how you find that out but that will be for another time cuz im exploding
wait yeah i understand the part
but how can i find it out
in a simpler way instead of doing it one by one until i get 1024
other ways we won't be able to solve this question....there're only 10 expressions
that is (a-b)²
huh
so the only way is doing it one by one
oh yeah now I understood what she meant.....however let's talk about after solving this question.
idk whats happening xd
I also barely understand, they gave her olimpic questions after just teaching binomial expressions.
🤣
I think so.
ahhh okay but even after doing it
@woeful scroll can you repost the original question?
i stil have to somehow like power everything and find the answer?
like solve 2^2+1, 2^4+1, 2^2^10+1
wait thats different than the first one
noo you just need to multiply it by (2-1)
noting is going to change since (2-1) is 1 and if you multiply anything by 1 nothing changes.
like (2-1)(2^4+1) = (2^4+1)?
but that wont give the answer of what 2^4+1 is
noononono, look at my solution
I multiply (2-1) and (2+1) first
they become (2^2-1)
yeah i understand all that but at last u still have to find what 2^2^11 is right
then I multiply (2^2-1) with (2^2+1)
well it's 2^2048 and I think it's enough
the goal was simplify the expression ig . In the test you will have a)2^2^11,b)2^1024 etc...
ehhh i guess but honestly i wouldnt have seen the expression as a2-b2
i hope cuz its
now you know how to solve this kinda of questions
not multiple choice
yeahhh
i ust have to
observe better
so 2^2^10 its equal to 2^1024 right
if you just write 2^2^11 everthing will be ok.
yep
okok
now ill go do other questions
tysm
(watch me ask for help again in the forum in the next sec)
alright, just ping me
honestly, how is a2-b2 (a-b)(a+b)
like the (a+b)^2 thing i can understand easily bcz its bracketed then only the power
but that
how do i separate it to understand it in a similar way as a+b)^2
hm i think i got it
great!!
write down it by yourself as well to understand it more efficiently
hold on a sec so green( what i always do) is wrong
cuz i never knew u can do like red( what u did), so meaning its possible to separate the a+b when multiplying?
OH
I DID THE GREEN WNOGLY
search up multiplication properties
so its the same
ah yes i just messed up cuz i messed up
wait what
so green is correct
and red is ??
its the whole (a+b) multiplied by the whole (a-b)
correct
AHH I GET IT
green wrong red correct
green is wrong when you go to the 2nd step
new green i checked again
yes
so new green = red
this one is wrong on the 2nd step
red one is correct
huhhhhhh
yeah, so what can't you understand?
so don't do it!!!!
the green mistake is you did
(a+b)(a-b) = a + b(a-b)
like how did u just separate out the (a+b) to multiply w (a-b), thats possible?
isnt that the same thing
its like
the purpose of the bracket
no different
is to signal multiplication
oh
what
ive been doing math for 14 years and knowing it today
the same as b(a-b) + a
like expanding right
always do multiplications this way.
hmm wait
if you lose the brakets you are just multiplying the b now
and before you were multiplying the whole (a+b)
like
3+2(1+1) is different from (3+2)(1+1)
oh so its like
3+2x(1+1) and (3+2) x (1+1)
just put real number in the formula first calculate it without the formula then apply the formula and you will understand how does it work
yeah, when we use brackets we usually dont add the x sign
so (a+b)x(a-b) = (a+b)(a-b)
its not important to understand how it works right
it is :)
that * is multiplying, but we usually dont write it if there is brackets
like when we say ab its a*b
idk if there is any more doubts
wait do i do (a^2-b^2) + (a^2-b^2) + (a^2-b^2) to find a^6-b^6
so its like 3 (a+b)(a-b)
noooo it will be just 3(a^2-b^2)
i dont think so
which is 3(a+b)(a-b)
the formula
right
before making such a statement put numbers to prove it. for instance let's take a=2 b=1 so you're saying 3(2^2-1)=2^6-1 which is 9=63 which is not true!!!
the first sum isnt equal to 3(a+b)(a-b)
ohh erhh
whats the problem you are solving?
this
im trying to see if i can actually adapt to the questions w the formula
and guess like i cant
how did the ^2 expanded version beceom the ^3 expanded version
just rewrite a^6 as (a^3)^2
OOH YES
this is what i mean when i say i cant put formulas in questions
cuz im not observant
yeah thats exponents properties
wait so (a^3)^2 - (b^3)^2 = a^6-b^6 is ((a-b)(a^2+ab+b^2))^2
ah yes that ik
its just really hard to see with all of these symbols xd
true true
wait is this correct
you really mean ab^2 or (ab)^2
now thats different than the pic 🫠
oh what
yes a^3-b^3 becomes (x-y) and a^6-b^6 becomes x^2-y^2
so im replacing an unknown term with another unknown term
ahhhhhh i feel like thats overcomplicating the original question which is to simplify
yeah and in the future you will do it a lot,
we're doing this to make you see which formular to apply
there's no formula for a^6-b^6
so that wee need to use a^2-b^2 formula
oh wtf thats what ive been trying to find
cuz i thought u can make a^3-b^3 somehow that
ugh ill solve this tmr its so late alrd
my brain needs a night to process this x.x
wait theres a formula for a^3-b^3 right
yea
yeah but's harder to implement, better use a^2-b^2
no stress, you will understand it all
Wait if I use (a^2)^3
use (a^3)^2 instead
But it's harder to implement isn't it
a^3 = (a-b)(a^2+ab+b^2)
Ehh I'll go zzz and hope I dream about it so I won't forget
yeah better go sleep
I figure it out, turns out the question is a bit wrong, the second part is (a^2-ab+b^2)
(a^6-b^6)/(a^3-b3) = (a^3)^2 - (b^3^2)/(a^3-b^3) = (a^3-b^3)(a^3+b^3)/(a^3-b^3)
Then cancel the same one and = (a^3+b^3)/(a^2-ab+b^2)= (a+b)(a^2-ab+b^2)/(a^2-ab+b^2)
And cancel the same one again = (a+b)
also
i remember someone up there mentioned sth about simultaneous equation thing
is that related to algebra?
like the thing im doing rn
cuz i got this
and i thin its simultaneous equation
rn im trying to do al the questions by myeslf but it seems impossible
if its simultaenous equation, some1 please teach me 
hi, I have no idea what simultaneous equation is however I can tell you that (a+b)^2 and (a-b)^2 formulas are kinda similar but the difference is 2ab part. Just substract one from another and you will find that (a+b)^2 equals to.
yeah i try that but it wont tell me what x and y each value right
wait
nvm
can i do like this
i feel like i cant
cuz itll make it to (x^2+y^2)(2xy)
stuck
oh wtf i did a mistake
(x-y)^2 does not equal to 8^2
stuck again
ando nce again im stuck
for the second line on the right, I believe you meant to write (x-y)^2 - also be careful when it comes to isolating your terms, to get rid of the 2(15) on the left side which is positive, you need to subtract 30 - opposite operations
also id recommend trying to let y(y+8)= -15, cos then you will definitely get a solution or two for y, so you can find what x is
Jesus what’s that? let’s say that (x+y)^2=p we need to find p then right? So let’s find what does p-(x-y)^2 equals to, (x+y)^2-(x-y)^2=x^2+2xy+y^2-(x^2-2xy+y^2)=4xy
Thus p-(x-y)^2=4xy and p=(x-y)^2+4xy so we know the values of xy and (x-y) all it takes now just replaces them with their values
ahh i get it now
so the goal is to
expand it so that u get xy and x-y then subsitute in the value
is it
ill try the other question:D
PLEASE TELL ME IM CORRECT??
i realize what i did wrong so this is the corrected (i guess) version?
AHHHHHHH IS IT CORRECT?
706
tell me im correct
im feelin gsmarter by each minute
how does this formula works? whats with the . . . in the middle
im tryna solve this
to feel smarter
another one
you’re still confusing the formula of a^2-b^2 however I’m glad seeing your progress. Here since you said x^4+y^4=p and we don’t have any formula for a^2+b^2 we can turn it into (a+b)^2 formula and we just need to add 2x^2*y^2. so p+2(xy)^2=(x^2+y^2)^2 and x^2+y^2 might be found through the formula a^2+b^2=(a-b)^2+2ab which were given to us.
huuh which part of a^2-b^2 did i got it wrong
ahh got it the mistake i did is (x^2)^2 + (y^2)^2 is not equal to (x^2-y^2)(x^2+y^2)
yes!!!
your should try another approach
erhh okay let me try again
okay
((x-y)^2+2xy)^2-2(xy)^2=(64-30)^2-2*15^2
bro, x^4+y^4 is NOT (x^2+y^2)^2
huh dont the power multiply w the 2?
to make it easier to understand let’s say that x^2=a and y^2=b them x^4 will become a^2 and y^4 become b^2 do you agree with that?
agree
okay so we need to find a^2+b^2 right?
yeah
since we don’t have any formula for a^2+b^2 we need to find where it hides. For instance in the formula of (a+b)^2 which equals to a^2+b^2 +2ab. there a^2+b^2 = (a+b)^2 -2ab does that make sense to you?
yes
now let’s replace with the original values x^4+y^4 = (x^2+y^2)^2-2(xy)^2 is that clear?
so the formula but with extra ^2
this formula
👍 yes
we just replaced a with x^2 and b with y^2
ah so thats why at last its 1156-450
since xy is given so we can say
x^4+y^4 = (x^2+y^2)^2-450
cuz i did (x^2+y^2)+2(xy)^2 due to my wong undertanding
no problem
we will work with that
wait so techincally we can create formulas for like a^2+b^2 which doesnt have a formula?
basically yes, but whatever we are doing is just simple algebra from (a+b)^2 formula
that’s why we don’t memorize it
oh shi so theres even harder one x.x
wait dyk what this is
whats with the . . . in between
and the thetas thing
did you understand the solution of previous one?
yup
you won’t need formula
I had never seen a problem which needs this formula so far
oh…
I would just find the values of x and y if I were you
oh okk
just replace x=5/2-y and solve quadratic equation
but sth weird is that (5/2) ^ 2 is not 13/4
oh so ill just use the (a^2+b^2) = (a+b)^2 - 2ab formula
(x+y)^2 is (x+y)(x+y) and x^2+y^2 is x•x+y•y!!!!
you will just find what xy is but we need x it self so you need to replace y with 5/2-x and solve the quadratic equation
erhh okay holdon
what's a quadratic equation..?
ik it's similar to sth ystrdy
except for that nothing else
like this question
i find that x^2 = 25/4 - 25+y^2 and y^2 = x^2 = 25 - 25/4, ignoring quadratic equation cuz idk what that is
wait you don't know how to solve the equations like x^2-5x+3=0?
idk
like
my teacher said we haveto self learn it
cuz its not covered in the syllabus
means she expect us to know
just look it up and you will understand how to solve that question below.
or ask chatgpt what quadratic equation is
oh theres another formula for it .-.
because idk how explain it
yeah lol
the entire math is memorizing the formulas and performing them
i feel like if ik the concept it should be fine?
must it always be ( ) + ( ) + ( ) = 0
or can the = not be 0
even if it's not 0 we can substract it from both sides and get ( ) + ( ) + ( ) = 0
ah i think i get it, so ill jst have to memorize the formula and im goodto go?
wiat hold on ima put this quadractic equation thing on hold cuz i just realize i havet finish another hw due tmr .-.
ah nvm im done
yeah just memorize it,its proof is so complicated and even some university students don't know about it
so proof is not important
yes
our goal is just understand where to implement those formulas
wait but whats with the + - thing on the square root
yeah that means there're 2 solutions for this equation.
ohh one negative and positive
but rare one of them isn't true , and you have to decide which is our real x
but in this case both of them ok.
wait so x = 5/2 - y
the 5/2 - y is the entire quadratic formula
ik te formula but idrk how it works, chat gpt said theres a,b,c but wheres my abc
x, y, 5/2 ?
what the shi
do i haveto do this?
x+y=5/2 isn't a quadratic equation by it self, you should replace y=5/2-x and then apply it on the second equation. like : x^2+(5/2-x)^2=13/2 then use (a+b)^2 formula to ease it
and you will get ax^2+bx+c=0
(a+b)^2 or (a-b)^2 ?
x^4 - 25/4(x) = 1 /4
ah yess it feels like a st udent finding a mistake in the professor's working c:<
yeah😂
wait there no supposed to be x^4
and x^2+x^2=2x^2 not x^4!!!!
5+5=2*5=10 not 5^2 which is 25!!!
oh x.x i confused it with the add power thing
that's fine just don't it again
almost right but omit x
oh what we can just cancel of the x?
a,b and c are coefficients
yes
wait so does the ^2 for 2x^2 comes along
coefficient*(x^2)
yess
x = -5 + - square root 5^2 - 4(2)(1/4) / 4
+5*
isnt b = -5x = -5 tho
oh i get it -(-5) then - and - become +5
don't worry there's no formulas just applying previous ones
let's say x^5+y^5 is p
and we can get x^5 by x^2*x^3 that's why we multiply (x^2+y^2) with x^3+y^3
ah yes
now all it makes just finding xy and x^3+y^3 which is more easier
wait wiat why after x^5 + x^2 * y^3 + y^2 * x^3 + y*5 is p + x^2 * y^2 (x+y)
we can find x^3+y^3 by this formula
so x^5 + x^2 * y^3 + y^2 * x^3 + y5 is (x^3 + y^3)
ehh what im confused wiat let me process
I just rewrite the same thing in another order
let me test it out wait
okay no worries
it was just an example to show why it ends up outsite of the parentheses
ohh
so you get this part?
the bottom is the up one expanded version?
wait but when i do x^2y^2(x+y) i get x^3y^2 + y^3x^2
yes!!!
huh what bout this
I just substracted that x^2y^2(x+y) from both sides to find p
huh- wasn't there only one side this whole time
(x^2+y^2)(x^3+y^3)=p+x^2y^2(x+y)
ohh this thing
yaay!! finally!!! so we can begin finding the values of (x^3+y^3) and xy
(x^3 + y^3) = uhhh
create a new formula
liek the
(x^2 + y^2) right
yeah I've wrote it before, we got it from (x+y)^3 formula
huh
i jst realize i havent memorize the (x+y)^3 formula o-O
here\
fix it now!!!1
if I were you I would memorize it this way:
yess
hm idk but i feel like ill be able to somehow get it by multiplying (x+y) 3 times
so shouldnt be a big worry
but just slower
yes you can but why?
memorizing easier.
my memory is too small for all the maths formula
that im pretty sure there will be even more forthe future
and other subjects stuff
yes it's.....
soo i rather save it for sth that actually requires memory like the quadractic formula
for now ofc
but don't worry after some practice you will remember them all
i hope
you don't need it rn, since your teacher didn't teach you about it.
well we r kinda expected to know it so
you will see (x+y)^3 a lot!!! even in 11th grade
if she didn't tell about it then not. You can learn if you want
That's still a long period of time
But I guess
I'm so tired, just try to find x^3+y^3 and xy and ask chatgpt if something. If even chatgpt won't help then dm me.
poor kid
Oh wow
Hi again, it supposed to be -1/8
just raise (x+y) to the second power and you will see why.
xy
Huh I did (x+y)^2 = (5/2)^2
Then (x^2+y^2+2xy) = 25/4
And since x^2+y^2 = 13/4, it'll be 2xy=25/4-13/4
yo where is the task? 😭
12/4 = 3 = 2xy
Xy = 3/2
ya seems right
Either I'm wrong or I saw the question wrongly cuz I trust it's -1/8, it's prob another formula he was talking abt
I'm still testing ou the -1/8 tho
wait wasn’t x^2+y^2 =13/2?
you’re right then ,my bad
Oh oh oh
Oh lol. If I'm considered young at the age of 14 then u??
I substituted everything and it's -65/16
yep you’re a kid
14 kid t.t
I trust your answer. Too lazy to check
Ah yes
did you find x^3+y^3?
wasup unc
sup kiddo how is it going?
And substitute in the value
good
going good gang wbu
not bad, just took my medication for my back.
Postgraduate... How old is that
Ehh whatever I'll consider myself graduated from the binomial expression thimg
Thank you for your help guys
uhh idk like above 23
Oh that's not that old
says the 14 yrs old
Just a 10 yrs gap..?
lmfao
I’m only 18
k blud
Oh yeah and If u r old I should be consider as medium:D
Wait but postgraduate at 18???
Postgraduate of high school or uni
I have no idea what it is.
Just randomly picked
👍