Question

Given the function f (x) = x² + 8x + 7, what are the zeros of f?

Answer 1

Answer:

x = - 7, x = - 1

Step-by-step 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