A bicycle rental company charges a one time fee of 15 plus 4 for every hour of rental Part A Which recursive formula correctly models the cost in dollars of a rental for n hours a 1 4 a n a n 1 15 a 1 19 ain a n 1 15 a 1 19 a n a n 1 4 Part B How much will the bicycle rental cost in dollars for 7 hours Xa