Which of the following is a factor of the polynomial x^2-x-20?

A. x-5
B. x-4
C. x+2
D. x+5
E. x+10

Question

Which of the following is a factor of the polynomial x^2-x-20?

A. x-5
B. x-4
C. x+2
D. x+5
E. x+10

anonymous · Answer

do you know how to factor it first?

anonymous · Answer

I can't for the life of me remember how to do it. I haven't had a math class in roughly two years, and I have to take a placement test for class soon, so I've been doing some prep.

anonymous · Answer

ok what 2 numbers multiply together =20 and add together =1

anonymous · Answer

-5 and 4

jdoe0001 · Answer

$\large \begin{array}{cccllll}
 x^2&-x&-20\
&\uparrow&\uparrow \
&4-5&4\cdot -5 
\end{array}$

anonymous · Answer

correct. so now you have x^2-x-20=0-----> (x-5) and (x+4) now all u have to do is to check  which one will give you 0

anonymous · Answer

-5

anonymous · Answer

yeap

anonymous · Answer

u got it :D

anonymous · Answer

you know why "2 numbers multiply together =20 and add together =-1"?