SOLUTION: 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

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: 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      Log On


   

Question 1022072: 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
Found 2 solutions by Alan3354, fractalier:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Which of the following is a factor of the polynomial? x^2-x-20
-----------
Factor it.
Then you'll know.

Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
We factor this like this...
x^2 - x - 20
We say "what factors of 20 have a difference of 1?"
Well, that's easy, 5 and 4.
And since the middle term is -x, you know it must mean -5 and +4.
Then you arrange binomial factors, to UNFOIL the given trinomial...like this...
(x - 5)(x + 4)
Choice A.