Question

已知丨ab+2丨+丨a+1丨=0 ,则代数式1/(a-1)（b+1)+1/(a-2)(b+2)+…+1/(a-2009)

Answer 1

a=-1,b=2

1/(a-1)（b+1)+1/(a-2)(b+2)+…+1/(a-2009)x(b+2009) =-(1/2-1/3+1/3-1/4+…-1/2011)=-2009/4022