Let f(x)=4x +5 and g(x)=4x2 -5. What is (f*g) ( x-1)?

1 Answer
Jun 9, 2018

16x^3-28x^2-12x-1

Explanation:

"evaluate "(f*g)(x)=f(x)xxg(x)

(4x+5)(4x^2-5)=16x^3+20x^2-20x-25

"to evaluate "(f*g)(x-1)

"substitute "x=x-1" into "(f*g)(x)

=16(x-1)^3+20(x-1)^2-20(x-1)-25

=16(x^3-3x^2+3x-1)+20(x^2-2x+1)-20x+20-25

=16x^3-48x^2+48x-16+20x^2-40x+20-20x-5

=16x^3-28x^2-12x-1