Question

1.计算1+2-3-4+5+6-7-8+9+10-11-12+……+2005+2006-2007-20082.对有理数a

Answer 1

1

1+2-3-4+5+6-7-8+9+10-11-12+……+2005+2006-2007-2008

=(1+2-3-4)+(5+6-7-8)+...+(2005+2006-2007-2008)

=-4*502=-2008

2.（-3）*4

=(-3+4)-(-3-4)

=1-(-7)

=8

3

(a-1)-(b+2)=a-b-3=0故a-b=3>0故a>b

(a-1)-(c-3)=a-c+2=0故a-c=-2d

故有c>a>b>d