(+1)+(-2)+(+3)+(-4)+(+5)+(-6)+(+7)……(+2009)+(-2010)+(+2011)
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/27 11:24:05
![(+1)+(-2)+(+3)+(-4)+(+5)+(-6)+(+7)……(+2009)+(-2010)+(+2011)](/uploads/image/z/1782728-8-8.jpg?t=%28%2B1%29%2B%28-2%29%2B%28%2B3%29%2B%28-4%29%2B%28%2B5%29%2B%28-6%29%2B%28%2B7%29%E2%80%A6%E2%80%A6%28%2B2009%29%2B%28-2010%29%2B%28%2B2011%29)
(+1)+(-2)+(+3)+(-4)+(+5)+(-6)+(+7)……(+2009)+(-2010)+(+2011)
(+1)+(-2)+(+3)+(-4)+(+5)+(-6)+(+7)……(+2009)+(-2010)+(+2011)
(+1)+(-2)+(+3)+(-4)+(+5)+(-6)+(+7)……(+2009)+(-2010)+(+2011)
1-2+3-4+5-6+7-…+2009-2010+2011-2012
=-1-1-1……-1
=1006x(-1)
=-1006
1006,(前2010项是-1005)