If 5000 Feet of Fencing Are Used to Enclose a Rectangular

Multiple Choice

If 5000 feet of fencing are used to enclose a rectangular field, the resulting area of the field is A=x(2500-x) , where x is the width of the pen. What is the maximum possible area of the pen?

A) 62,500ft²
B) 1,562,500ft²
C) 1250ft²
D) 31,250ft²