Length (L): 2w - 1
width (w): w
Area (A) = L · w
28 = (2w - 1) · (w)
28 = 2w² - w
0 = 2w² - w - 28
0 = 2w² - 8w + 7w - 28
0 = 2w(w - 4) + 7(w - 4)
0 = (2w + 7) (w - 4)
2w + 7 = 0 , w - 4 = 0
w = -
, w = 4
Since width cannot be negative, disregard -
Length (L) = 2w -1 → L = 2(4) - 1 → L = 8 - 1 → L = 7
Answer: 7