(1 pt) A fence is to be built to enclose a rectangular area of 310 square feet.

(1 pt) A fence is to be built to enclose a rectangular area of 310 square feet. The fence along three sides is to be made of material that costs 5 dollars per foot, and the material for the fourth side costs 13 dollars per foot. Find the length L and width W (with W leq L) of the enclosure that is most economical to construct.