<u>ANSWER</u>


<u>EXPLANATION</u>
To find the value of a function, f(x) at a given value x=a, we plug in x=a into f(x) to obtain f(a) in simplified form.
The first function is

To find f(7), we substitute x=7, into the function.

The second function is

To find f(4), we replace x with 4 to obtain,


Her total bill is $186 because :
(3x39)+15+(2x27)