Marna wants to find the values of x for which the funciton below will have a value of 10. f(x) = x^2 + x - 20. Which of the following shows the correct factorization of this funciton for f(x) = 10.

Question

A. (x + 5) (x + 4) = 10
B. (x - 5) (x - 4) = 10
C. (x + 6) (x - 5) = 0
D. (x + 5) (x - 6) = 0

Please explain how you reached that answer.

Answer 1

f(x)=10=x^2+x-20

x^2+x-30=0
(x+6)(x-5)=0