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