An athlete plans a 12-mile run. If the athlete runs 4 miles each hour, h, which expression represents the number of miles the athlete has left in the run after running for h hours

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