Answer:
f(x+6)= 3x + 30
Step-by-step explanation:
Whenever you have to evaluate a function with a certain value, replace the variable x with a certain value. In this case, substitute x with the value of (x+6). You get the equation f(x+6)= 3(x+6) + 12, which simplifies into f(x+6)= 3x + 18 +12, which further simplifies into f(x+6)= 3x + 30.
