(1/2010-1)*(1/2009-1)*(1/2008-1).(1/1001-1)*(1/1000-1)

问题描述:

(1/2010-1)*(1/2009-1)*(1/2008-1).(1/1001-1)*(1/1000-1)

=(-2009/2010)(-2008/2009)(-2007/2008).(-1000/1001)(-999/1000)
=-999/2010