用簡便的方法計算.(-9)³;×(-3分之2)³;×(3分之1)³;

用簡便的方法計算.(-9)³;×(-3分之2)³;×(3分之1)³;


(-9)³;×(-3分之2)³;×(3分之1)³;
=(9×3分之2×3分之1)³;
=2³;
=8



812+197+78的簡便運算
111


加法交換律、結合律
812+197+78 =(812+78)+197 = 890 +197 = 1087