Arectangle is drawn so that the width is 3 feet shorter than the length. the area of the rectangle is 40 square feet. find the length of the rectangle.

Draw a rectangle and label the right side as L-3 and the bottom side as L.

Area is L x W...in this case L(L-3) = 40we get

L^2 - 3L = 40  (subtract 40 from each side we get...)
L^2 - 3L - 40 = 0  (factor this out to get the L and W)

8 and 5