Answer:
x = - 7, x = - 1
Explanation:
To find the zeros let f(x) = 0 , that is
x² + 8x + 7 = 0
Consider the factors of the constant term (+ 7) which sum to give the coefficient of the x- term (+ 8)
The factors are + 7 and + 1 , since
7 × 1 = + 7 and 7 + 1 = + 8 , then
x² + 8x + 7 = 0
(x + 7)(x + 1) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 7 = 0 ⇒ x = - 7
x + 1 = 0 ⇒ x = - 1