1、y-x/x²-y²2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z)

问题描述:

1、y-x/x²-y²
2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z)

1 1/x+y
2 -1