Question

如果有理数a和b满足等式|ab-2|+|1-b|=0,试来1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+

Answer 1

=1、a=2

1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+…+1/(a+2011)(b+2011)=1/1×2+1/2×3+.+1/2012×2013

=1-1/2+1/2-1/3+.+1/2012-1/2013=1-1/2013=2012/2013