苏州纳米门户:(1-1/2005)+(1-2/2005)+(1-3/2005)+..............(1-2003/2005))+(1-2004/2005)

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/04 06:36:29

(1-1/2005)+(1-2/2005)+(1-3/2005)+..............(1-2003/2005))+(1-2004/2005)
=[(1-1/2005)+(1-2004/2005)]+[(1-2/2005)+(1-2003/2005)]+[(1-3/2005)+(1-2002/2005)]+.......+[(1-1002/2005)+(1-1003/2005)]
=1+1+1+.....1(共1002项)
=1002

(1-1/2005)+(1-2/2005)+(1-3/2005)+..............(1-2003/2005))+(1-2004/2005)
=(1+1+..+1)-(1/2005+2/2005+..+2004/2005)
=2004 - (1+2+....+2004)/2005
=2004 - 2004*2005/(2*2005)
=2004 - 1002 = 1002

原式=2004-(1/2005+2/2005+····+2004/2005)=2004-1002=1002

解:(1-1/2005)+(1-2/2005)+(1-3/2005)+..............(1-2003/2005))+(1-2004/2005)
=1+1+....+1-(1/2005+2/2005....+2004/2005)
=2004-(1+2+3+4+...2004)/2005
=2004-1002
=1002

答案=1002

(1-1/2005)+(1-2/2005)+(1-3/2005)+…(1-2003/2005))+(1-2004/2005)
=(2004/2005+2003/2005+2002/2005+…+1/2005)*2004÷2
=1*2004÷2
=1002