lyonlmt
春芽
共回答了11个问题采纳率:81.8% 举报
(1/2009-1)×(1/2008-1)×(1/2007-1)×····×(1/1000-1)
=(1/1000-1)×(1/1001-1)×...×(1/2007-1)×(1/2008-1)×(1/2009-1)
=(1-1/1000)×(1-1/1001)×...×(1-1/2007)×(1-1/2008)×(1-1/2009)
=999/1000*1000/1001×...×2006/2007×2007/2008×2008/2009
=999/2009
1年前
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