分式x²-y²/xy-xy-y²/xy-x²可化简为()

问题描述:

分式x²-y²/xy-xy-y²/xy-x²可化简为()

原式=(x²-y²)/xy-y(x-y)/[-x(x-y)]
=(x²-y²)/xy+y/x
=(x²-y²+y²)/xy
=x²/xy
=x/y