Question

Given the functions, fx) = x - 8 and g(x) = x2 + x - 1, perform the indicated operation. When applicable, state the domain

restriction

Answer 1

A

Explanation:

(fg)(x) = f(x) × g(x)

= (x - 8)(x² + x - 1)

Each term in the second factor is multiplied by each term in the first factor, that is

x(x² + x - 1) - 8(x² + x - 1) ← distribute both parenthesis

= x³ + x² - x - 8x² - 8x + 8 ← collect like terms

= x³ - 7x² - 9x + 8 → A

There are no restrictions on the domain.