Let's make W = width, and L = length.
What do we know? We know that P = 40 yards, and L = W + 1.5 .
The formulas for perimeter and area are:
P = 2W+2L
A = W*L
We can set P to 40, and since L = W+1.5, we can substitute that in for L.
40 = 2W + 2 (W+1.5)
40 = 2W + 2W + 3
37 = 4W
W = 37/4
We can plug that into L to find the length.
L = W + 1.5
L = 37/4 + 3/2
L = 43/4
Now, we plug into the area formula!
A = L*W
A = 43/4 * 37/4
A = 1591/16 or 99.43 yd^2