由∣ab-2∣+∣1-b∣=0,得ab-2=0,1-b=0,则 a=2,b=1.
1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+…+1/(a+2004)(b+2004)
=1/1×2+1/2×3+1/3×4+…+1/2005×2006
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+ … +(1/2005-1/2006)
=1-1/2006
=2005/2006.
由∣ab-2∣+∣1-b∣=0,得ab-2=0,1-b=0,则 a=2,b=1.
1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+…+1/(a+2004)(b+2004)
=1/1×2+1/2×3+1/3×4+…+1/2005×2006
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+ … +(1/2005-1/2006)
=1-1/2006
=2005/2006.