（27／8﹚的x-1次幂乘2／3的2x-3次幂=4／9
(3^3/2^3)^(x-1)*(2/3)^(2x-3)=(2/3)^2
(3/2)^(3x-3)*(2/3)^(2x-3)=(2/3)^2
(2/3)^(3-3x)*(2/3)^(2x-3)=(2/3)^2
(2/3)^(3-3x+2x-3)=(2/3)^2
(2/3)^(-x)=(2/3)^2
-x=2
x=-2