问题描述： 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 1个回答 分类：数学 2014-11-30 问题解答： 我来补答 先化简[(x²+y²)-(x-y)²+2y(x-y)]/4y [(x²+y²)-(x-y)²+2y(x-y)]/4y =[x²+y²-(x²+y²-2xy)+2xy-2y²]/4y=[x²+y²-x²-y²+2xy+2xy-2y²]/4y=[4xy-2y²]/4y=[4x-2y]/4=2*(2x-y)/4=(2x-y)/2=1 展开全文阅读
