Jamie has saved $42 of her allowance money to buy books. If she buys 5 books at d dollars per book, she will have 42-5d of her allowance left. How much does she have left if the books cost $3.50 each?
First, you plug in 3.50 for d. Then, you multiply 5 and 3.50 and get 17.50. After that, you subtract 17.50 from 42 , and you get 24.50. That means that Jamie will have $24.50 of her allowance left.
