绝对值里面开出来都为负值,所以变号,原式化为
|1/2005-1/2003|+|1/2003-1/2001|+...|1/7-1/5|+|1/5-1/3|+|13-1|
=1/2003-1/2005+1/2001-1/2003+.+1/5-1/7+1/3-1/5+1-1/3
=-1/2005+1
=2004/2005
绝对值里面开出来都为负值,所以变号,原式化为
|1/2005-1/2003|+|1/2003-1/2001|+...|1/7-1/5|+|1/5-1/3|+|13-1|
=1/2003-1/2005+1/2001-1/2003+.+1/5-1/7+1/3-1/5+1-1/3
=-1/2005+1
=2004/2005