Question

Find (f.g)(x) where f(x) = 3x + 1, g(x) = 2x + 7.

=
O (f•9)(x) = 6x2 + y 3x + 7
O (f.g)(x) = 6x2 + 7
O (fºg)(x) = 6x2 + 23x + 7
O(fºg)(x) = 5x + 8

Answer 1

3rd option

Explanation:

(f • g)(x)

= f(x) × g(x)

= (3x + 1)(2x + 7)

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

3x(2x + 7) + 1(2x + 7) ← distribute parenthesis

= 6x² + 21x + 2x + 7 ← collect like terms

= 6x² + 23x + 7