1118点 ,9*((1+7)/3)(9*(1+7))/39*((7+1)/3)(9*(7+1))/39/(3/(1+7))(9/3)*(1+7)9/(3/(7+1))(9/3)*(7+1)((1+7)*9)/3(1+7)*(9/3)(1+7)/(3/9)((1+7)/3)*9((7+1)*9)/3(7+1)*(9/3)(7+1)/(3/9)((7+1)/3)*9