320x39+68x390简算
58x39 1.5x390十73x61的简算 -
58x39+1.5x390十73x61 =58×39+15×39+73×(100-39)=58×39+15×39+7300-73×39 =39×(58+15-73)+7300 =7300。
58x39+1.5x390十73x61 =58×39+15×39+73×(100-39)=58×39+15×39+7300-73×39 =39×(58+15-73)+7300 =7300。