Note that...for any given perimeter, the area is at a max when L = W.
So let L=W and so that LW = max area
Now, if we decrease W by 1 and increase L by 1, we have
(W - 1) (L +1) = WL + (W-L) -1 = max area + 0 - 1 = max area - 1
And if we decrease W by 2 and increase L by 2, we have
(W - 2)(L+2) = WL + 2(W-L) - 4 = max area + 0 - 4 = max area - 4
And with successive increases/decreases of n = 3, 4, 5.......etc., the max area is decreased by n^2. So, the smallest of these decreases occurs between n = 0 and n = 1. Or, looking at it from another perspective, inceasing the Width from (W -1) to W and decreasing the Length from (L+1) to L ( where W = L), results in x = 1.
