高考问答工银e生活2.05下载:帮忙解一下这道数学题！谢谢大家了！
来源：百度文库 编辑：高考问答 时间：2024/05/11 16:02:05
[（x-1)/(x-2)-(x-2)/(x-3)-(x-3)-(x-4)+(x-4)/(x-5)]/(2x-7)
首先，题目打错了，应是
[（x-1)/(x-2)-(x-2)/(x-3)-(x-3)/(x-4)+(x-4)/(x-5)]/(2x-7)
原式＝[（x-2＋1)/(x-2)-(x-3＋2)/(x-3)-(x-4＋3)/(x-4)+(x-5＋4)/(x-5)]/(2x-7)
＝[1+1/(x-2)-1-1/(x-3)-1-1/(x-4)+1+1/(x-5)]/(2x-7)
=[1/(x-2)-1/(x-3)-1/(x-4)+1/(x-5)]/(2x-7)
={[1/(x-2)+1/(x-5)]-[1/(x-3)+1/(x-4)]}/(2x-7)
={(2x-7)/[(x-2)(x-5)]-(2x-7)/[(x-3)(x-4)]}/(2x-7)
=1/[(x-2)(x-5)]-1/[(x-3)(x-4)]
=2/[(x-2)(x-5)(x-3)(x-4)]