设：长为x 宽为y
x-3=y+2
(x-3)(y+2)=xy
x-y=5
2x-3y=6
2x-2y=10
2x-3y=6
-2y-(-3y)=10-6
y=4
x=5+y
x=5+4
x=9
长方形的长是9cm,宽是4cm.