The width of a rectangle is increased by 20%. The length of is decreased by x%, so that the area remains the same. What is x?
+37159 l * w = k k = constant
x l * 1.2 w = k
x l * w = k / 1.2
l * w = k / (1.2 * x) remember l x w = k
k = k / (1.2 * x) or 1.2 * x must = 1
x = 1/1.2 = .8333 the width has decresed by ~ 17 %
