let L the length and let W the width of the rectangle. we have L * W = 96 (1) and L-W = 4 (2)
from the (2) we get L = W+4 replacing the L in (1) we have (W + 4)W = 96 -->>> W^2 + 4W - 96 = 0
solving for W we get two values for W. W1=-12 and W2 = 8 we keep the second one W = 8 since we
can not have a negative value for a dimention of the rectangle. So L - 8 = 4 from (2) and L=12
Check : 12 x 8 = 96 and 12-8 = 4
