What is the value of 1 -2 + 3 - 4 + 5 -6 + 7... - 2004 + 2005 - 2006 + 2007?

Results 1 to 2 of 2

- April 20th 2007, 12:52 PM #1

- Joined
- Sep 2006
- Posts
- 75

- April 20th 2007, 12:57 PM #2

- Joined
- Nov 2005
- From
- someplace
- Posts
- 14,972
- Thanks
- 4

1 -2 + 3 - 4 + 5 -6 + 7... - 2004 + 2005 - 2006 + 2007 =

......................1 +(-2 + 3) + (- 4 + 5) + (-6 + 7)... +(- 2004 + 2005) + (- 2006 + 2007)

There are 1003 bracketed terms each of which has value 1, and an additional

1 at the beginning, so the sum is 1004.

RonL