2007/2008x2009=2007/2008x(2008+1)=2007/2008 x2008+2007/2008=2007又2007/20082009分之2008*2008=2008/2009x2008=2008/2009x(2009-1)=2008/2009x2009-2008/2009=2008-2008/2009=2007又1/2009思路是把整数部分拆成...