2008 power of 2006x1 - 2008x1 + 2009 =? Why 2007!

2008 power of 2006x1 - 2008x1 + 2009 =? Why 2007!

First, the 2008 power of 1 = 12008 * 1 = 2008
Then the original decline 2006-2008 + 2009
=-2+2009
=2007