A farmer plans to build a rectangular pen adjacent to a river out of the 800 ft of fencing he has in storage. This means he only needs to enclose three sides of the region (see picture below). y Xx Number (A) Find Area of the enclosed region as a function of the width of the region, x. (Submit your answer in factored form) A (x) = (B) What is the maximum area the farmer can enclose? ft x= Number Y A (C) What dimension should be used to create the pen of maximum area? X - Number ft ft