1. Isaac goes to an amusement park where tickets for the rides cost $10 per sheet and tickets for the shows cost $15 each.
(a) Write an expression that describes the amount of money Isaac will spend if he buys x sheets of the tickets for rides and y tickets for shows.
(b) Evaluate the expression to find the total price that Isaac will pay if he buys 5 sheets of tickets for rides and 3 tickets for shows.