(-0.5)+(-15又3分之1)+(+17.5)+(-12又3分之2)

问题描述:

(-0.5)+(-15又3分之1)+(+17.5)+(-12又3分之2)

(-0.5)+(-15又3分之1)+(+17.5)+(-12又3分之2)即:(-0.5)+(-(15+1/3))+(+17.5)+(-(12+2/3))=-0.5-(15+1/3)+17.5-(12+2/3)=-0.5+17.5-15-1/3-12-2/3=17-15-12-(1/3+2/3)=17-15-12-1=-11