Packaging Costs

A rectangular box is to have a square base and a volume of$60$ft$3.$ The material for the base costs$42/$ft$2,$ the material for the sides costs $10/$ft$2,$ and the material for the top costs$34/$ft$2.$ Lettingxdenote the length of one side of the base, find a function in the variablexgiving the cost $($in dollars$)$ of constructing the box