1/a（a+1）+1/(a+1)(a+2)+...+1/(a+2007)(a+2008)这题怎么做?

来源：学生作业帮编辑：神马作文网作业帮分类：综合作业时间：2024/11/13 00:30:10

1/a（a+1）=1/a-1/(a+1)
所以1/a（a+1）+1/(a+1)(a+2)+...+1/(a+2007)(a+2008)=1/a-1/(a+1)+1/(a+1)-1/(a+2)+...+1/(a+2007)-1/(a+2008)中间项消掉了
=1/a-1/(a+2008)=2008/a(a+2008)

(a 1)(a 2)(a 3)(a 计算1/a(a+1)+1/(a+1)(a+2)+...+1/(a+2007)(a+2008)+1/(a+2011)(a+ 计算1/a(a+1)+1/(a+1)(a+2)+...+1/(a+2007)(a+2008) a/a-1÷（a-a/2a-1) a(a-1)(a-2)(a-3)(a-4)因式分解（5a的二次方+2a-1)-4(3-8a+2a的二次方）怎么做? 化简a(a+2)-（a-1)(a+1）【1】a+a=a×a a= [ ]【2】a×a=a÷a a=[ ]【3】a×a=a－a a=[ ] [4]a－a=a＋a （高一集合）已知A={2,4,a*a*a-2a*a-a+7},B={1,a+3,a*a-2a+2,a*a*a+a*a+3 （a+1/a）*=a*+2+1/a* (a-1/a)*=a*-2+1/a* 计算：1/a(a+1)+1/(a+1)(a+2)+...+1/(a+2006)(a+2007) （a－ 2a/a）÷1-a² / a²+a