sally pizza charges a base price of $13 for a large pizza plus $1.20 for each additional topping .  a. find a function f that models the price of a pizza with x toppings ..  b. . find the inverse of the function from part 1 . what does f-1 represent ?  f-1 (x) = _____ f-1(x) represents = _____     if pizza cost $20.20 , how many topping does it have ? use the inverse function from part b to solve the problem.