已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y

已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y
已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y

已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y
x/y=1/2
y=2x
2x/(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

设X=a，Y=2a,代进去算就OK了