|1/2009-1/2008|-|1/2008-1/2007| =1/2008-1/2009-1/2007+1/2008 =-1/2009-1/2007 =-4016/4032063
问题描述：
|1/2009-1/2008|-|1/2008-1/2007| =1/2008-1/2009-1/2007+1/2008 =-1/2009-1/2007 =-4016/4032063
答
不对
应该是2/2008-1/2009-1/2007
如果中间是加号,则=1/2009-1/2007=-4016/4032063