1/1x2+1/2x3=1/3x4+...+1/2005x2006+1/2006x2007=

问题描述:

1/1x2+1/2x3=1/3x4+...+1/2005x2006+1/2006x2007=

等同于 1-1/2+1/2-1/3+1/3-1/4+...+1/2006-1/2007=2006/2007