【(x+y)²-(x+y)(x-y)】÷2y其中x=-2011y=2012

问题描述:

【(x+y)²-(x+y)(x-y)】÷2y其中x=-2011y=2012

【(x+y)²-(x+y)(x-y)】÷2y
=[x²+2xy+y²-x²+y²]÷2y
=[2xy+2y²]÷2y
=x+y
=-2011+2012
=1