I REALLY NEED HELP, IT'S AN EMERGENCY!! WILL MEDAL

Question

anonymous · Answer

Here's a picture of the problem

preetha · Answer

You could pay for Qualified Help.

anonymous · Answer

I don't have the money

anonymous · Answer

@ganeshie8 @mathmate @paki @rishavraj @Bookworm14

just_one_last_goodbye · Answer

Still need help @rosebud4612flvs ? ^_^

mathmate · Answer

Solve by comparison,
y=2x^2-1
y=-4x+1

Since both right-hand sides equal to y, you only have to equate them to get:
(y=)2x^2-1=-4x+1
Transpose terms to get an expression ....=0 which matches one of the answers.

anonymous · Answer

I think I'm good; When I did it by myself I got x^2+2x-1=0

mathmate · Answer

You have probably missed a (-1) from the second equation.

just_one_last_goodbye · Answer

No problem ^_^ we believe everyone deserves an education but... it would be nice if you could get some qualified helper to help :) see... the people helping can give you a wrong answer but our QH help with a 100% step by step help and we can assure you that the answer will be correct (or your money back)

anonymous · Answer

I don't have money for a QH

imqwerty · Answer

don wrry :)

just_one_last_goodbye · Answer

^ agreed ^_^

anonymous · Answer

Okay, so I know it's not C or D

anonymous · Answer

The one's would cancel out right?

anonymous · Answer

which would leave B?

mathmate · Answer

@just_one_last_goodbye 
Are you suggesting that non QH will give a wrong answer and QH will not?

imqwerty · Answer

$$-4x+1=y=2x^2-1$$$$-4x+1=2x^2-1$$can u find the answer now :)

anonymous · Answer

?

anonymous · Answer

@mathmate is B correct?

mathmate · Answer

Follow what @imqwerty  is working out for you.
We're using the same method.
@rosebud4612flvs

imqwerty · Answer

ok 
we know that-
$$y=-4x+1$$and also that$$y=2x^2-1$$
so -4x+1 and 2x^2-1 are both equal to y so they both are equal
so we can write$$-4x+1=2x^2-1$$did u understand this step?@rosebud4612flvs

anonymous · Answer

Yes, I understand that step. What do I do next?

anonymous · Answer

Do I have to combine the x's?

just_one_last_goodbye · Answer

@mathmate I am stating that some non QH will probably give you a direct answer. and it might be wrong. Not all tho ^_^ Forgive me if I said it wrong

anonymous · Answer

Okay so would I do 2x^2-1+(-4x+1)?

anonymous · Answer

ugh

anonymous · Answer

I think I did that wrong

mathmate · Answer

@just_one_last_goodbye 
whew!  it's a little more clear!

imqwerty · Answer

yes :) its correct so now u have this-$$-4x+1-(-4x+1)=2x^2 - 1 -(-4x+1)$$ now open the brackets

anonymous · Answer

okay so the first part cancels out

anonymous · Answer

and that leaves me with 2(x^2−1+2x)

anonymous · Answer

is that correct?

imqwerty · Answer

yes and what about the right hand side

anonymous · Answer

is it 2(x^2−1+2x)

anonymous · Answer

would it be C?

anonymous · Answer

x^2+2x-1=0

imqwerty · Answer

no, what did u get on opening the bracket on the right hand side?

anonymous · Answer

on the right hand side I got 2(x2−1+2x)

imqwerty · Answer

yes that is correct :D 
so now we have-
$$0=2(x^2-1+2x)$$opening the bracket u get-$$0=2(x^2)+2(-1)+2(2x)$$$$0=2x^2-2+4x$$ thas ur answer :)

anonymous · Answer

should it have been 2x^2-1+4x+1?

anonymous · Answer

oh wait forget that

anonymous · Answer

THANK YOU SO MUCH

imqwerty · Answer

have u understood how we got the answer ?

anonymous · Answer

It was correct :) and I understand it so much better now thank you

imqwerty · Answer

np (: