Answer:
72
Step-by-step explanation:
[tex]f(x) = 4x+8\\g(x) = x + 4\\\\1. f(g(x)) = 4(x+4) + 8\\2. f(g(x)) = 4x + 16 + 8\\3. f(g(x))=4x + 24\\\\4. f(g(12)) = 4(12) + 24\\5. f(g(12)) = 48 + 24 = 72\\[/tex]
To do these, you have to place the entire function inside the parent function's variables.
You are inputting the value of the function g(x) into f(x)