Question

X=1/9,Y=-3时,求代数式（x+2y^2）+(2x+1/1*2y^2)+...+(2007x+1/2007*200

Answer 1

X=1/9,Y=-3时,

代数式（x+2y^2）+(2x+1/1*2y^2)+...+(2007x+1/2007*2008y^2)

=(x+2x+...+2007x)+(2y^2+1/1*2y^2+...+1/2007*2008y^2)

=(1+2+...+2007)x+(2+1/1*2+...+1/2007*2008)y^2

=2007*(2007+1)/2x+(2+1-1/2+...+1/2007-1/2008)y^2

=2007*1004*1/9+(2+1-1/2008)*(-3)^2

=2007*1004*1/9+(2+1-1/2008)*(-3)^2

=223892+27-9/2008

=223864又1999/2008