|ab-2|+|1-b|=0
1-b=0,b=1
ab-2=0,a=2
ab分之1+(a+1)(b+1)分之1+(a+2)(b+2)分之1++(a+2007)(b+2007)分子
=1/1*2+1/2*3+1/3*4+...+1/2008*2009
=1-1/2+1/2-1/3+1/3-1/4+.+1/2008-1/2009
=1-1/2009
=2008/2009
|ab-2|+|1-b|=0
1-b=0,b=1
ab-2=0,a=2
ab分之1+(a+1)(b+1)分之1+(a+2)(b+2)分之1++(a+2007)(b+2007)分子
=1/1*2+1/2*3+1/3*4+...+1/2008*2009
=1-1/2+1/2-1/3+1/3-1/4+.+1/2008-1/2009
=1-1/2009
=2008/2009