Answer:
Amount of times he goes to the car wash.
Step-by-step explanation: Variable x represents the amount of times he goes to the car wash because we already know he spends $85 a year for his membership and then again $7 everytime he goes. That means the last variable left is how many times he goes in that year. So say if he goes 5 times in a year, it would be y=7(5)+85 which equals 120. So he would have paid $120 for going to the carwash 5 times and being an annual member.
Hope this helps!