计算:(+1)+(-3)+(+5)+(-7)……+(+2009)+(-2011)

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计算:(+1)+(-3)+(+5)+(-7)……+(+2009)+(-2011)

计算:(+1)+(-3)+(+5)+(-7)……+(+2009)+(-2011)
计算:(+1)+(-3)+(+5)+(-7)……+(+2009)+(-2011)

计算:(+1)+(-3)+(+5)+(-7)……+(+2009)+(-2011)
把括号去掉
就是
1-3+5-7+9-11……+2009-2011
=(1-3)+(5-7)+(9-11)……+(2009-2011)
=-2-2-2……-2
=-2*503
=-1006

应该是2012/4=503。
答案=-2*503=-1006

(+1)+(-3)+(+5)+(-7)……+(+2009)+(-2011)
=[(+1)+(-3)]+[(+5)+(-7)]……+[(+2009)+(-2011)]
=-2×503
=-1006