How do i solve for an inverse for example:

f(x)=1/3x+12

Avery has saved $295 to spend on christmas gifts for 11 people. which is the best estimate of the amount he can spend for each person?

The volume of a cone is 37x3 cubic units and its height is x units. which expression represents the radius of the cone's base, in units? 1 s o 3x o 6x obx 93x2

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.