计算:20022-20012+20002-19992+19982-…+22-12.

问题描述:

计算:20022-20012+20002-19992+19982-…+22-12

原式=(2002+2001)(2002-2001)+(2000+1999)(2000-1999)+…(2+1)(2-1)
=2002+2001+2000+1999+1998+…+2+1
=

(2002+1)×2002
2

=2005003.