Question

If f(x) = 5x − 1 and g(x) = 2x2 + 1, what is the value of (f × g)(-3)?

Answer 1

f(x) = 5x − 1 and g(x) = 2x^2 + 1

(f × g)(x) =  (5x − 1)(2x^2 + 1)

(f × g)(x) = 10x^3 - 2x^2 + 5x - 1

Substitute x = - 3

(f × g)(-3) = 10(-3)^3 - 2(-3)^2 + 5(-3) - 1

(f × g)(-3) = 10(-27) - 2(9) -15 - 1

(f × g)(-3) =-270 - 18 - 16

(f × g)(-3) = -236

Answer

- 236