1.1又4/17乘2又2/3减3/4的差加15又1/12除以7/21=(5/4*8/30)-3/4+(181/12*21/7)=(5/1*2/30)-3/4+(181/4*7/7)=10/3-3/4+181/4(通分)=(40-9+543)/12=574/12=287/62.41又1/3*3/4+51又1/4*4/5+61又1/5*5/6=(124/3*4/3)+(2...