(1+7)/(3/9)((1+7)/3)*9((1+7)*9)/3(1+7)*(9/3)(7+1)/(3/9)((7+1)/3)*9((7+1)*9)/3(7+1)*(9/3)9*((1+7)/3)(9*(1+7))/39/(3/(1+7))(9/3)*(1+7)9/(3/(7+1))(9/3)*(7+1)9*((7+1)/3)(9*(7+1))/3这是电脑算的。
(1+7)×(9÷3)=24