Which represents the imverse of the function f(x) = 4x?

Need on this one asap im almost done with this subject

Axel follows these steps to divide 40 by 9: start with 40. 1. divide by 9 and write down the remainder. 2. write a zero after the remainder. 3. repeat steps 1 and 2 until you have a remainder of zero. examine his work, and then complete the statements below.

Ian is in training for a national hot dog eating contest on the 4th of july. on his first day of training, he eats 4 hot dogs. each day, he plans to eat 110% of the number of hot dogs he ate the previous day. write an explicit formula that could be used to find the number of hot dogs ian will eat on any particular day.