问题描述: x+1分之1 - x的平方-6x+9分之3-x * x-3分之x的平方+x等于多少?其中x=根号2 1个回答 分类:数学 2014-12-05 问题解答: 我来补答 原式=1/(x+1)*[(x-3)/(x+3)^2+2/(x+3)]-x/(x+3)(x-3)=1/(x+1)[3(x+1)/(x+3)^2]-x/(x+3)(x-3)=3/(x+3)^2-x/(x+3)(x-3)=[3(x-3)-x(x+3)]/(x+3)^2(x-3)=-(x^2+9)/(x+3)^2(x-3). 展开全文阅读