Answer:
length = 14 m
width = 7 m
Explanation:
l = length
w = width
l = 2w - 8
w(2w - 8) = 42
2w² - 8w - 42 = 0
you can factor out a 2 to work with smaller numbers:
w² - 4w - 21 = 0
(w - 7)(w + 3) = 0
w = 7
'w' cannot equal a negative so we discount it as an answer
find length:
l = 2(7) - 8
l = 14 - 8 or 6m