Renting a bicycle costs $15 for the first hour and $5.50 for each additional hour. Let x represent the number of additional hours. if you have $25 to spend, which of the following equations could be used to find how many hours you can rent a bicycle?
A. 5.5x + 15=25
B. 15x + 5.5 =25
C. 5.5x -15=25
D. 15x -5.5=25