19又9分之4+9又19分之4÷(2又9分之7+1又19分之6) =175/9+175/19÷(25/9+25/19) =175/9+175/19*9*19÷(25/9*9*19+25/19*9*19) =175/9+175*9÷(25*19+25*9) =175/9+175*9÷(25*28) =175/9+9/4 =700/36+81/36 =781/36 追问：看不懂