Maths

1.(x^-1y/x^0y^-2)^2
=(y^3)/(x^2)
=(y^6)/(x^2)

2.2^-1x2^2y-5/4^-3
=2^(-1+2y-5)/2^(-6)
=2^(2y-6)/2^(-6)
=2^(2y-6+6)
=2^2y

2007-03-08 08:24:17 補充：
1.(x^-1y/x^0y^-2)^2=[(y^3)/(x^2)]^2=(y^6)/(x^2)