Please help me on these 3!!

What is the inverse of the function f(x) = 2x + 1?

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.

Find the length of the normal and the angle it makes with the positive x-axis. (see pictured below)