If the graph of an inverse passes the you know it is a function

Given f(x) = 17-x^2what is the average rate of change in f(x) over the interval [1, 5]?

Need asap. solve for the following inequality

Liz is shipping a package to her friend. the maximum weight of a medium flat-rate box is 20 pounds, including the box which weighs 6 ounces. write and solve an inequality to describe the possible weight in pounds, w, of the contents that liz will ship to her friend if she must use a medium flat-rate box. use the drop-down menus to explain your answer.