# How do you factor # -x^2+7x+18#?

##### 1 Answer

May 12, 2015

Use the new AC Method to factor trinomials.

Compose factor pairs of (c = 18) and look for the pair whose sum is

(b = 7). Proceed: (-1, 18)(-2, 9). Since a < 0, Then, p = 2 and q = -9.

Factored form:

Check: Develop f(x) = -(x^2 - 7x - 18) = -x^2 + 7x + 18. Correct.