Question

Each week, Alfonso earns $85 for every shift he works at the theater and $15 for every dog-walking job. He uses the expression 85x + 15y to keep track of his earnings.

Answer 1

So you didn't put an actual question. To find the money he makes you just plug in the numbers.
If he works 4 shifts at the theater you replace x with 4. Then, you find 85 x 4. You do the same thing with 15y.