Casey uses some of his savings on batting practice. the cost of renting a batting cage for 1 hour is $6. he rents a cage for 9 hours in each of two months. what is the change in casey's savings after two months? i have to use integers.

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax