1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)+...1/(x+2005)(x+2006)=1/2x+4024
问题描述:
1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)+...1/(x+2005)(x+2006)=1/2x+4024
答
有等式1/(x+1)(x+2)=1/(x+1)-1/(x+2)
所以左边=1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3).
=1/(x+1)-1/(x+2006)
后面就不用我说了吧 左右移一下统分就可以了