### Total Cost Equations

1. Allen bought 20 stamps at the post office in 37¢ and 20¢ denominations. If the total cost of the stamps was $7.06, how many 37¢ stamps did Allen buy? 2. The profit on a watch is given by P = x2 - 5x - 9 and where x is the number of watches sold per day. How many watches were sold on a day when there was a $15 loss?