Compute 1 - 2 + 3 - 4 +... + 2005 - 2006 + 2007 - 2008 + 2009 - 2010.
(1 - 2) + (3 - 4) + (5 - 6) + ... + (2003 - 2004) + (2005 - 2006) + 2007
= -1+(-1)+(-1) (1005 times)
= -1005
You eventually get:
-1 + -1 + -1 + 2007(for 1005 terms)
So
-1005
uh I think it goes to -2010, not 2007
Whoops, thx for catching that @qjin27
