Question

A rectangular room needs 120 square feet of carpet?the width of the room is 2 feet less than its length. find the length and width of the room?

Answer 1

A = LW
A = 120
W = L - 2

120 = L(L-2)
120 = L^2 - 2L
L^2 - 2L - 120 = 0
(L - 12)(L + 10) = 0

L - 12 = 0
L = 12

L + 10 = 0
L = -10 (extraneous solution...will not work)

length (L) = 12 ft
width (W) = L - 2 = 12 - 2 = 10 ft