15^(2/3) * 3^(7/3) / 5^(-1/3) = 3^(2/3) * 5^(2/3) * 3^(7/3) * 5^(1/3) =
3^((2+7)/3) * 5^((2+1)//3) = 3^3 * 5^1 = 27 * 5 = 135
15^(2/3) * 3^(7/3) / 5^(-1/3) = 3^(2/3) * 5^(2/3) * 3^(7/3) * 5^(1/3) =
3^((2+7)/3) * 5^((2+1)//3) = 3^3 * 5^1 = 27 * 5 = 135