Finding (fg)(8) functions

Question

Let f(x) = x² + 3x and g(x) = 1 - x

Find (fg)(8)

Answer 1

(fg)(8) is stating multiplication of functions f and g and then substituting 8 for x. It may be easier to do the substitution of 8 into both functions first and then multiplying the results.

EX. f(8)=8²+3(8) = 64+24 = 88 g(8) = 1-8 = -7

So (fg)(8) = 88•-7 = -616