-1+3-5+7.-2005等于几

问题描述:

-1+3-5+7.-2005等于几

-1+501*(-2)=-1003

原式=2×1003-1003=1003

-1+3-5+7.-2005
= [-1+3]+[-5+7]+[-9+11].+[-2001+2003]-2005
= 2*1002/2-2005
= -1003