<PRE><B>Question 845902</B>
A farmer needs to build a rectangular corral for his animals.
 He has 200 yards of fencing available.
 He needs to make 4 pens. 
 What is the largest corral he can create?
:
To make 4 pens he needs 4 times the width of the corral, therefore:
2L + 4W = 200
Simplify, divide by 2
L + 2W = 100
L = (100-2W)
Total area
A = L * W 
replace L with (100-2W)
A = (100-2W)*W
A = -2W^2 + 100W
A quadratic equation, max area occurs at the axis of symmetry; x = -b/(2a)
W = {{{(-100)/(2*-2)}}}
W = +25 yds is the width that gives max area
Find Length
L = 100 - 2(25)
L = 50 yds length for max area
Find max area
50 * 25 = 1250 sq/yds</PRE>