1.2-4分之1×3分之2÷1又9分之7÷12分之1 = 2-1/6*9/16*12 =2-9/8 =7/8 2.5分之4×3分之2+5分之1÷4分之3 =8/15+1/5*4/3 =8/15+4/15 =12/15 =4/5 3.(5分之1+10分之33×30分之1-8÷300）÷4分之1 =(1/5+33/300-8/300)...