Solve the quadratic equation

5x^2-8x=8-5x

Question

Solve the quadratic equation 

5x^2-8x=8-5x

aveline · Answer

How do we start?

hannahc234 · Answer

We start by adding 5x to both sides

aveline · Answer

Right. We want one side to be equal to zero. So after we add 5x to both sides, we subtract 8 from both sides$$5x ^{2}-3x-8=0$$

aveline · Answer

What do we do next?

hannahc234 · Answer

Factor?

aveline · Answer

Right

caozeyuan · Answer

why not just plug numbers into the solution equation, factoring seems to be kind of difficulty

xcior12 · Answer

wassup u dome retrice c-u-n-t-s

xcior12 · Answer

fck openstudy

xcior12 · Answer

it sucks a ssss

xcior12 · Answer

like ur mother

aveline · Answer

@mathmale 
We need a moderator

xcior12 · Answer

so does this d-i-c-k

aveline · Answer

@caozeyuan 
Plugging numbers in may get you the right answer, but it would take forever. Not to mention that you might not even find all the possible answers.

xcior12 · Answer

ave stop talking before buffy the white boy slayer come for ur retrice

xcior12 · Answer

a\ssss

xcior12 · Answer

ill make yall shut the fck down going through all questions  and messing with people

welshfella · Answer

and  if you are studying quadratic equations  you have to learn how to factor them.

caozeyuan · Answer

but the solution equation ganratees all solutions will be found, and factoring is hard espeicially if you have complex conjugate roots

aveline · Answer

@Hero 
@ganeshie8 
We need a moderator here please

xcior12 · Answer

oh u back did buffy  the white boy slayer get ur a/////sss

aveline · Answer

@HannahC234 
So sorry about this. Do you need help factoring?

hannahc234 · Answer

Yes please

aveline · Answer

Ok, 5x^2-3x-8=0
For factoring a quadratic, we need to find what will add up to -3x and what will multiply to be negative 8:

(5x-?)(x+?)

hannahc234 · Answer

Okay. I'm still kinda lost

aveline · Answer

(5x-8)(x+1) is the next step. Do you know how to FOIL?

hannahc234 · Answer

Yes

aveline · Answer

So if we FOIL, (5x-8)(x+1) equals:
5x^2+5x-8x-8
or 5x^2-3x-8

We know that  (5x-8)(x+1) is equal to zero. So:
5x-8=0
AND
x+1=0

Can you simplify these equations to find the values of x?

hannahc234 · Answer

-1 and 8/5 would be the answer correct?

mathmale · Answer

Hannah:  Substitute (-1) for x in the original equation.  is the equation then true or false?  That will tell you whether or not -1 is a solution.

hannahc234 · Answer

So it would be -1?

aveline · Answer

"-1 and 8/5 would be the answer correct? "
Both of those would are the right answers. If you plug them into the original equation, you'll see that they work.