I need help plz plz plz help me ASAP. And SHOW YOUR WORK

Answer:
The cost of the wristband for 8 rides is $35.
Step-by-step explanation:
The expression for the cost, C, for r rides is
C = 2.5r + 15
Since she wants to go on 8 rides, r is 8.
Substitute r with 8 in the cost equation and evaluate it.
C = 2.5r + 15
C = 2.5 * 8 + 15
C = 20 + 15
C = 35
The cost of the wristband for 8 rides is $35.