Answer:
fg(7) = 231
Explanation:
The question is asking you to find fg(7), which is function of f times function of g when x = 7. To solve it, you just need to plug in the 7 where x is in both equation and then multiply these results.
f(x) = x + 4
f(7) = 7 + 4
= 11
g(x) = 3x
g(7) = 3(7)
= 21
fg(7) = 11 × 21 = 231