The formula is
YC x YD = AY x YB
fill in what we know:
18 x 6 = 9 x YB
108 = 9 x YB
YB = 108 / 9
YB = 12
3x² - 39x + 36
3(x²) - 3(13x) + 3(12)
3(x² - 13x + 12)
3(x² - 12x - x + 12)
3(x(x) - x(12) - 1(x) + 1(12))
3(x(x - 12) - 1(x - 12))
3(x - 1)(x - 12)
First compute the perimeter of the pool:
(21+33)*2=108 foot.
Since the material cover 232 ft^2, then it is sufficient to divide the above number over the length of the border like this:
232/108=2.1
The trip can be 2.1 ft in wide.
