脱式计算:(3-112.5%+2又1/7)×1又8/13÷3又1/56= (1又7/8+2又1/7)×1又8/13÷3又1/56 =3又1/56×1又8/13÷3又1/56 =3又1/56÷3又1/56×1又8/13 =1又8/137又1/5÷0.24-2又2/7×0.875=7.2÷0.24-16/7×7/8=30-2=28
得数是28吧!