# unFOILing

• Sep 1st 2009, 12:38 PM
greg9510
unFOILing
how do you unFOIL the following?

-xsquared+x+12=0

Im not sure how to do this because the x squared was negative. I thought it was:

(-x+4)(x+3)

So x would equal what? negative 4 or positive 4 since the x beside the four is negative?

Thank You!!!
(Thinking)
• Sep 1st 2009, 12:57 PM
masters
Quote:

Originally Posted by greg9510
how do you unFOIL the following?

-xsquared+x+12=0

Im not sure how to do this because the x squared was negative. I thought it was:

(-x+4)(x+3)

So x would equal what? negative 4 or positive 4 since the x beside the four is negative?

Thank You!!!
(Thinking)

Hi greg9510,

$-x^2+x+12=0$

$-(x^2-x-12)=0$

$-(x-4)(x+3)=0$

$(-x+4)(x+3)=0$

$-x+4=0 \ \ or \ \ x+3=0$

$x=4 \ \ or \ \ x=-3$