need help to solve please see attached

A rectangular box is to have a square base and a volume of 20 fto. The material for the base costs 39c/ft , the material for the sides costs 10/ft, and the material for the top costs 32c/ft . Let x denote the length of one side of the base. Find the area of each side of the box, in terms of x. Top of the Box = One Side of the Box = Bottom of the Box = Find a function in the variable x giving the cost (in dollars) of constructing the box. f( x ) =