If f (x) = 12x^2-5 and g (x) = x+7 find (f•g) (x)

12x^3 + 84x^2 - 5x - 35

Step-by-step explanation:

multiply both of the polynomials together

12x^2 - 5 * x + 7

First, multiply x with everything

12x^2 - 5 * x = 12x^3 - 5x

then, multiply 7 by everything

12x^2 - 5 * 7 = 84 ^2 - 35

Last, add both of them together

12x^3 - 5x + 84x^2 - 35 = 12x^3 + 84x^2 - 5x - 35

12x^3 + 84x^2 - 5x - 35