1+2+3+4+5+…+2005+2006(1−1/1004)(1−1/1005)(1−1/1006)…(1−1/2005)(1−1/2006)=_.
问题描述:
=______. 1+2+3+4+5+…+2005+2006 (1−
)(1−1 1004
)(1−1 1005
)…(1−1 1006
)(1−1 2005
)1 2006
答
原式=
=1+2006+2+2005+…+1003+1004
×1003 1004
× 1004 1005
… 1005 1006
×2004 2005
2005 2006
=40260421003×2007
1003 2006
故答案为:4026042.