Let L be the length and W be the width. The equations that represents the given conditions are,
(1) L = W + 3
(2) A = (L - 1) x (W - 1) = 150
A = (W + 3 - 1) x (W - 1) = 150
The value of W is 11.8389 in. The width is therefore, 11.8389 in and the length is 14.8389 in.