Answer:

Step-by-step explanation:
We are given the function:

We want to find f(3), so we must substitute 3 in for x.

Solve according to PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition, and Subtraction.
Solve the exponent first.

Multiply 8 and 3.

Add.

For the function given, f(3) is 30.