2008/(1998*1999)+2008/(1999+2000)+…2008/(2007+2008)=2008*(1/(1998*1999)+1/(1999+2000)+…+1/(2007+2008))=2008*(1/1998-1/1999+1/1999-1/2000+…+1/2007-1/2008)=2008*(1/1998-1/2008)=2008/1998-1=10/1998=5/...