已知x=2007,y=2008,求x²-2xy+y²/5x²-4xy÷x+y/5x-4y+x²-y/x

问题描述:

已知x=2007,y=2008,求x²-2xy+y²/5x²-4xy÷x+y/5x-4y+x²-y/x

x²-2xy+y²=(x-y)²=(-1)²=1