
Callie H. answered 01/28/19
National Board Certified Teacher can help you/your child in all areas
The formula for finding the area of a rectangle is L x W = A.
And you know that L = W + 6 (length is width plus 6).
Now you know two of the variables to plug into the first equation.
(W+6) x W = 27
Distribute the W. W^2 + 6W = 27.
Move the 27 over.
W^2 + 6W -27 = 0
Use FOIL backward to solve.
(w + 9 )(w - 3 ) == WxW = W^2 (First); -3w (Outside); 9w (Inside); 9 x -3 = -27 (Last)
Set each of those equal to 0 and solve for W.
W+9 = 0
W-3 = 0
So W either equals -9 or 3. And since you can't have a negative length, W must equal 3, and L must equal 9 (3+6). And if you check your work, 3 x 9 = 27, which is your area.