>>236
実数の範囲であれば
-(3/4)*(2/9) = -(1/6)

16 = 2^4
16^(-1/6) = 2^(-2/3)

(1/27) = 3^(-3)
(1/27)^(-1/6) = 3^(1/2)

よって
(16/27)^(1/6) = 2^(-2/3) *3^(1/2)