1-3+5-7+9-11+……+2005-2007+2009

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/12 07:03:11
1-3+5-7+9-11+……+2005-2007+2009

1-3+5-7+9-11+……+2005-2007+2009
1-3+5-7+9-11+……+2005-2007+2009

1-3+5-7+9-11+……+2005-2007+2009
1-3+5-7+9-11+……+2005-2007+2009
=(1-3)+(5-7)+(9-11)+……+(2005-2007)+2009
=(-2)×1004÷2+2009
=-1004+2009
=1005

1-3+5-7+9-11+……+2005-2007+2009
=-2*1004/2+2009
=-1004+2009
=1005

<-2>*502+2009=1005

(1-3)+(5-7)+……+(2005-2007)+2009
=(-2)*((2005-1)/4+1)+2009

1-3+5-7+9-11+……+2005-2007+2009
=(1-3)+(5-7)+(9-11)+……+(2005-2007)+2009
=(-2)×1004÷2+2009
=-2008+2009
=1