The greatest common factor of 64 and 96 is 32, so, the first step after finding the great common factor is convert and rewrite "64 + 96" into distributive property.
You should get 32(2 + 3)
L = 2W
P = 2L + 2W
Plug 2W in for L.
54 = 2(2W) + 2W
54 = 4W + 2W
54 = 6W
Divide both sides by 6
W = 9
L = 2* 9
L = 18
A = L * W
A = 9 * 18
A = 162 units^2