Question 343278
"length of the rectangle is 4 times its width" ___ L = 4W


"the perimeter is 90y" ___ 2L + 2W = 90y


substituting ___ 2(4W) + 2W = 90y ___ 10W = 90y ___ W = 9y


substituting ___ L = 4(9y) ___ L = 36y


A = L * W = 36y * 9y = 324y^2