问题描述: 计算:-4/(x^2-4)-1/(2-x) x-7/(x-3)+1/3-x 1个回答 分类:数学 2014-12-05 问题解答: 我来补答 -4/(x^2-4)-1/(2-x)=-4/(x+2)(x-2) + 1/(x-2)=(-4+x+2)/(x+2)(x-2)=(x-2)/(x+2)(x-2)=1/(x+2) x-7/(x-3)+1/(3-x)=x - 7/(x-3) - 1/(x-3)=(x^2-3x-7-1)/(x-3)=(x^2-3x-8)/(x-3) 再问: 第二题貌似错了 再答: (x-7)/(x-3)+1/(3-x) x-7 是分子吗? =(x -7)/(x-3) - 1/(x-3) =(x-7-1)/(x-3) =(x-8)/(x-3) 展开全文阅读