
if 1 inch is added, you would add 2 inches to to each side of rectangle. Â
You would have: W+2, and, L+2, Â
Now let W+2 = x and, L+2 = y Â
Total area = Â x*y=M Â
If 1 inch is added again, like above you add 2 inches to both sides, you would then have:
(x+2)(y+2)=M+52; Â
xy+2x+2y+4=M+52; Â
xy=M
2x+2y=48 Â
x+y=48/2=24 Â
Now solve :
W+2+ L+2=24 Â
W+L=20 Â
The perimeter is 2(W+L)=20*2 = 40 inches.