27 = 3³
81 = 3⁴
(1/3) = 3⁻¹
3⁴ x (3³)⁻³ x (3⁴)^(2/3) : (3⁻¹)⁻² =
3⁴ x 3⁻⁹ x 3^(8/3) : 3² =
3⁻⁵ x 3^(8/3) : 3² =
3^(-5+8/3) : 3² =
3^(-15/3 + 8/3) : 3² =
3^(-7/3) : 3² =
3^(-7/3 - 2) =
3^(-7/3 - 6/3) = 3^(-13/3)
