(1/2013-1)乘(1/2012-1)乘(1/2010-1)乘....乘(1/1001-1)乘(1/1000-1)?
应该是(1/2013-1)乘(1/2012-1)乘(1/2011-1)乘(1/2010-1)乘....乘(1/1001-1)乘(1/1000-1)吧?
如果是的话:
解:
(1/2013-1)乘(1/2012-1)乘(1/2011-1)乘(1/2010-1)乘....乘(1/1001-1)乘(1/1000-1)
=(1/2013-1)×(1/2012-1)×(1/2011-1)×(1/2010-1)×……×(1/1001-1)×(1/1000-1)
=(2012/2013)×(2011/2012)×(2010/2011)×(20091/2010)×……×(1000/1001)×(999/1000)
=(2012×2011×2010×2009×……×1000×999)/(2013×2012×2011×2010×……×1001×1000)
=999/2013
=333/671
如果楼主确认是(1/2013-1)乘(1/2012-1)乘(1/2010-1)乘....乘(1/1001-1)乘(1/1000-1)的话:
解:
(1/2013-1)乘(1/2012-1)乘(1/2010-1)乘....乘(1/1001-1)乘(1/1000-1)
=(1/2013-1)乘(1/2012-1)乘(1/2010-1)乘....乘(1/1001-1)乘(1/1000-1)乘(1/2011-1)除以(1/2011-1)
=(1/2013-1)×(1/2012-1)×(1/2011-1)×(1/2010-1)×……×(1/1001-1)×(1/1000-1)÷(1/2011-1)
=(2012/2013)×(2011/2012)×(2010/2011)×……×(1000/1001)×(999/1000)×(2011/2010)
=(2012×2011×2010×……×1000×999)/(2013×2012×2011×……×1001×1000)×(2011/2010)
=(999/2013)×(2011/2010)
=2008989/4046136
=669663/1348710
=
中间漏了*(1/2011 -1)吧?直接减,然后分数相乘,发现中间可以抵消的
最后只剩下1/2013 * 999=333/671