-1+3-5+7-9+11...-2009+2011

问题描述:

-1+3-5+7-9+11...-2009+2011

-1 + 3 - 5 + 7 - 9 + 11...- 2009 + 2011
= (-1 + 3) + (- 5 + 7) + (- 9 + 11) + ... + (-2009 + 2011)
= 2×503
= 1006

原式
=2×2012×1/2×1/2
=1006

我计算错喽