(2)原式=
20082(2008?2)?2006 |
20082(2008+1)?2009 |
2006(20082?1) |
2009(20082?1) |
2006 |
2009 |
(3)原式=(1+2)(1-2)+(3+4)(3-4)+(5+6)(5-6)+…+(99+100)(99-100)
=-1-2-3-4-5-6-…-99-100
=-5050.
20083?2×20082?2006 |
20083+20082?2009 |
20082(2008?2)?2006 |
20082(2008+1)?2009 |
2006(20082?1) |
2009(20082?1) |
2006 |
2009 |