1+(-2)+3+(-4)+5+…+2009+(-2010)=_.

问题描述:

1+(-2)+3+(-4)+5+…+2009+(-2010)=______.

原式=(1-2)+(3-4)+…+(2009-2010)=(-1)×

2010
2
=-1005.
故答案是-1005.