## Algebra 2 (1st Edition)

$(15-0.5r)$ dollars
The total cost of the tickets is equal to the product of the number of tickets bought and the cost per ticket. Thus, $r$ raffle tickets would cost a total of $r(0.50) = 0.5r$ dollars. The remaining money can be found by deducting the cost of the tickets from $\$15\$. Thus, the amount of money left is: $$(15-0.5r)\text{ dollars}$$