If you do 2.50*5 (because Ms. Ortiz borrows $2.50 every day for 5 days) it equals 12.5, and since it's how much she owes, you have to make it negative, so it's -12.50 or she owes $12.50 (the first one if you are supposed to have the answer be negative, the second one if you have to have it in money form).
