The length of the longer side of rectangle r is 10 percent more than the length of a side of square s. The length of the shorter side of rectangle r is 10 percent less than the length of a side of square s. What is the ratio of the area of rectangle r to the area of square s? Express your answer as a common fraction.
Any help would be much appreciated! 
+36916 s= square side
then areas ratio becomes:
(s+.1s)(s-.1s) / (s * s) =
s^2 - .01s^2) / s^2
(1- .01)/1 = .99/1 = 99/100
