已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y
问题描述：
已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y
答
x/y=1/2y=2x2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y=2x/(x-y)²*(x+y)(x-y)/(x+y)+2y/(x-y)=2x/(x-y)+2y/(x-y)=2(x+y)/(x-y)=2(x+2x)/(x-2x)=6x/-x=-6