3.1×3/8+37.5%×5.9+0.375 =3.1×0.375+0.375×5.9+0.375 ×1 =(3.1+5.9+1)×0.375 =10×0.375 =3.75
3.1×3/8+37.5%×5.9+0.375＝3.1×0.375+0.375×5.9+0.375＝0.375×（3.1+5.9+1）＝0.375×10＝3.75
