A = LW
A = 144
L = W + 7
144 = W(W + 7)
144 = W^2 + 7W
W^2 + 7W - 144 = 0
(W - 9)(W + 16) = 0
W - 9 = 0
W = 9
W + 16 = 0
W = -16.....this is an extraneous solution and will not work
So W = 9
L = W + 7
L = 9 + 7
L = 16
so ur dimensions are : Length = 16 in. and Width = 9 in....and area = (9 * 16) = 144 in^2