Evaluate the given equation for the indicated function values. pls help

The answer in each numeral is:

Step-by-step explanation:

To obtain the result in each case, you must replace the variable (n) by the value that appears in the second case, I'll explain it with the first exercise:

As you can see, in the second doesn't appear f(n), but f(4), that means you must replace the "n" in the equation by 4, if we do this, we obtain:

The first answer is 28, now we'll continue with the next exercises:

In this form, you can prove the answers are: 28, -19, -33, and -9 respectively.