Answer:
length = 7 meters
Step-by-step explanation:
l = length
w = width
w = 3×l - 6
l×w = 105 m²
l×(3×l - 6) = 105
3×l² - 6×l = 105
l² - 2×l = 35
l² - 2×l - 35 = 0
solution of a squared equation is
(-b ± sqrt(b² - 4ac))/(2a)
a = 1
b = -2
c = -35
(2 ± sqrt(4 - 4×-35))/2 = (2 ± sqrt(4+140))/2 =
(2 ± sqrt(144))/2 = (2 ± 12)/2 = 1 ± 6
l1 = 1+6 = 7 meters
l2 = 1-6 = -5 meters, which did not make any sense for an actual object.
so, l = 7 meters remains.
