34分之3÷19分之4x12分之17=3/34×19/4×17/12=1/2x19/4×1/4=19/32
(3/34)/(4/19)*(17/12)=(3/34)*(19/4)*(17/12)=(3/34)*(17/12)*(19/4)=1/8*(19/4)=19/32
3/34÷4/19×17/12=3/34×17/12×19/4=19/32