If you would like to know the expression for the amount of money William earned last week, you can calculate this using the following steps:
$13 per hour
h hours ... at the concession stand
three times as many hours = 3 * h hours ... at the ticket counter
h hours + 3 * h hours = 4 * h hours of work last week
4 * h * $13 = $52 * h
The expression for the amount of money William earned last week would be $52 * h.
