Answer:
C
Step-by-step explanation:
Given
x² + 7x = 8 ( subtract 8 from both sides )
x² + 7x - 8 = 0
Consider the factors of the constant term (- 8) which sum to give the coefficient of the x- term (+ 7)
The factors are + 8 and - 1, since
8 × - 1 = - 8 and 8 - 1 = 7, thus
(x + 8)(x - 1) = 0
Equate each factor to zero and solve for x
x - 1 = 0 ⇒ x = 1
x + 8 = 0 ⇒ x = - 8
Solutions are x = 1 ; x = - 8 → C
