math functions 8th grade

Question

Terry and Shaquan went to the fair. The cost to get into the fair is $5 and food and ride tickets cost $0.50 each. The equation y=.5x+5 represents this function where y is the total cost and x is the number of tickets purchases. If Terry buys 15 tickets and Shaquan buys 21 tickets, how much more money does Shaquan spend at the fair?

Answer 1

5 times 21-15= $30 more, spent by Shaquan than Terry

Terry spent 5(17)+5 = 90

Shaquan spent 5(21)+5 = 120

120-90= $30