(+1)+(-2)+(+3)+(-4)+...+(+2005)+(-2006)+2007.这道题怎么算
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 05:33:40
![(+1)+(-2)+(+3)+(-4)+...+(+2005)+(-2006)+2007.这道题怎么算](/uploads/image/z/5299741-37-1.jpg?t=%28%2B1%29%2B%28-2%29%2B%28%2B3%29%2B%28-4%29%2B...%2B%28%2B2005%29%2B%28-2006%29%2B2007.%E8%BF%99%E9%81%93%E9%A2%98%E6%80%8E%E4%B9%88%E7%AE%97)
(+1)+(-2)+(+3)+(-4)+...+(+2005)+(-2006)+2007.这道题怎么算
(+1)+(-2)+(+3)+(-4)+...+(+2005)+(-2006)+2007.这道题怎么算
(+1)+(-2)+(+3)+(-4)+...+(+2005)+(-2006)+2007.这道题怎么算
太简单了
将上式两两结合得到
{[(+1)+(-2)]+[(+3)+(-4)]+……[(+2005)+(-25006)]}+2007
前边是1003个-1相加最后再加一个2007所以最后结果是-1X1003+2007=1004
看不懂的话继续追问
(+1)+(-2)+(+3)+(-4)+...+(+2005)+(-2006)+2007.
=2007-2006/2
=2007-1003
=1004
1004