2001-1998+1995-1992+…+15-12+9-6+3.

问题描述:

2001-1998+1995-1992+…+15-12+9-6+3.

(2)2001-1998+1995-1992+…+15-12+9-6+3,
=(2001-1998)+(1995-1992)+…+(15-12)+(9-6)+3,
=[(2001÷3-1)÷2]×3+3,
=[666÷2]×3+3,
=333×3+3,
=1002.