问题描述: 已知x+y=-4,xy=-12,求(x+1/y+1 )+ ( y+1/x+1)的值要写过程啊 1个回答 分类:数学 2014-12-05 问题解答: 我来补答 x+y=-4,则(x+y)²=x²+2xy+y²=(-4)²=16所以x²+y²=16-2xy=16+24=40(x+1/y+1 )+ ( y+1/x+1)=(x+1)²/[(x+1)(y+1)]+(y+1)²/[(x+1)(y+1)]=[(x+1)²+(y+1)²]/[(x+1)(y+1)]=(x²+y²+2x+2y+2)/(xy+x+y+1)=(40+2×(-4)+2)/(-12-4+1)=34/(-15)=-34/15 展开全文阅读