0.3×5又9分之4÷5又16分之11×6又21分之4+3.75÷1又8分之1
=0.3×49/9÷91/16×130/21+15/4÷9/8
=3/10×49/9×16/91×130/21+15/4×8/9
=49/30×16/91×130/21+10/3
=56/(15×13)×130/21+10/3
=(8×10)/(15×3)+10/3
=16/9+10/3
=46/9