To find the value of fg(4), we need to compute g(4) first and then apply the function f to that result.
1. Calculate g(4):
g(x) = 2x + 5
g(4) = 2(4) + 5 = 8 + 5 = 13
2. Now that we have g(4) = 13, we will plug this into the function f:
f(x) = 3x²
f(g(4)) = f(13) = 3(13)²
3. Calculate 13² and then multiply by 3:
13² = 169
f(13) = 3(169) = 507
Therefore, the value of fg(4) is 507.