(1-1/2008)+(2-1/2008*2)+(3-1/2008*3)+...+(2007-1/2008*2007)+2008-1/2008*2008)
=(1+2+3+……+2007+2008)*(1-1/2008)
=(1+2008)×2008/2×2007/2008
=2009×2007/2
=2016031.5
(1-1/2008)+(2-1/2008*2)+(3-1/2008*3)+...+(2007-1/2008*2007)+2008-1/2008*2008)
=(1+2+3+……+2007+2008)*(1-1/2008)
=(1+2008)×2008/2×2007/2008
=2009×2007/2
=2016031.5