Question

He length of a rectangular floor is 5 feet less than twice its width. the area of the floor is 150 square feet. what is the width of the room?

Answer 1

A = L * W
A = 150
L = 2W - 5

150 = W(2W - 5)
150 = 2W^2 - 5W
2W^2 - 5W -150 = 0
(2W + 15)(W - 10) = 0

2W + 15 = 0
2W = -15
W = -7.5 <== not this one

W - 10 = 0
W = 10 <===the width is 10
length is 2W - 5.....2(10) - 5....20 - 5....15