=4分之3*(5分之1+5分之4)=4分之3*1=4分之3
原式=(3/4)*(1/5)+(3/4)*(4/5) =(3/4)*【(1/5)+(4/5)】 =(3/4)*1 =0.75
3/4 x 1/5 + 3/4÷1/8得 3/4(1/5+8) 后面自己算一下吧
3/4×20%+3/4÷125%=3/4×1/5+3/4×4/5=3/4×(1/5+4/5)=3/4×1=3/4