Answer:
(k + 9)(k - 8)
Step-by-step explanation:
Given
k² + k - 72
Consider the factors of the constant term ( - 72) which sum to give the coefficient of the k- term ( + 1)
The factors are + 9 and - 8, since
9 × - 8 = - 72 and 9 + 8 = + 1, hence
k² + k - 72 = (k + 9)(k - 8)
