杭州交通信息网李准基最新电视剧:难题巧解（初三）
来源：百度文库 编辑：杭州交通信息网 时间：2024/04/28 07:09:18
(x+2)/(x+1)-(x+3)/(x+2)-(x-4)/(x-3)+(x-5)/(x-4)
请帮忙解这道题，麻烦写出分析及过程
请帮忙解这道题，麻烦写出分析及过程
(x+2)/(x+1)-(x+3)/(x+2)-(x-4)/(x-3)+(x-5)/(x-4)=
1+1/(x+1)-1-1/(x+2)-1+1/(x-3)+1-1/(x-4)
=1/(x+1)+1/(x-3)-1/(x+2)-1/(x-4)
=(x-3+x+1)/(x+1)(x-3)-(x-4+x+2)/(x+2)(x-4)
=2(x-1)/(x+1)(x-3)-2(x-1)/(x+2)(x-4)
=2(x-1)[(x+2)(x-4)-(x+1)(x-3)]/(x+1)(x-3)(x+2)(x-4)
=-10(x-1)/(x+1)(x-3)(x+2)(x-4)
你可以先通分,在计算啊!