Question

Given f(x) = 3 and g(x) = 5x + 7, find (f + g)(-8).

Answer 1

-30

Explanation:

f(x) = 3 so f(-8) = 3;

g(x) = 5x + 7, so g(-8) = 5(-8) + 7 = -33

Then (f + g)(-8) = 3 - 33 = -30

This is the sum of two functions both evaluated at x = -8.