15 = w(2w - 1)
15 = 2w2 - w
2w2 - w - 15 = 0
(2w + 5)(w - 3) = 0
Either 2w + 5 or w - 3 (or both) have to be equal to 0 in order for them to multiply to be 0.
2w + 5 = 0
2w = -5
w = -5/2
This answer is out because we don't measure negatively.
w - 3 = 0
w = 3
2(3) - 1 = 5
5 m x 3 m