1/(1997×1998)+1/(1998×1999)+1/(1999×2000)+.1/(2005×2006)+1/(2006×2007)+1/2007
问题描述:
1/(1997×1998)+1/(1998×1999)+1/(1999×2000)+.1/(2005×2006)+1/(2006×2007)+1/2007
答
1/(1997×1998)+1/(1998×1999)+1/(1999×2000)+.1/(2005×2006)+1/(2006×2007)+1/2007
=1/1997-1/1998+1/1998-1/1999+...+1/2006-1/2007+1/2007
=1/1997