6y2−36 =0, 2.5x2= 40, (x+3)2=81 (ignore this part)
JD is repainting some of the walls in the classrooms at Golder. One wall has a width that is 4 feet less than its length. The wall has an area of 140 square feet. What is the length of the wall?
W = L - 4
Area = L * W
140 = L * ( L - 4)
140 = L^2 - 4L rearrange as
L^2 - 4L - 140 = 0 factor as
(L - 14) ( L + 10) = 0
The first factor set = 0 gives us what we want
L - 14 = 0
L = 14 (ft)