suppose that the market for racing bikes is perfectly competitive and that demand on this market is given by Q=62-2p. Furthermore, in the short run 6 firms are active in the market and all firms have the same cost function, given by C=q^2-4q.(Indeed,even in the short run firms do not face any fixed cost).

question:Determine the long-run equilibrium per-firm quantity supplied, the number of firms in the market in case there is free entry and exit.

答案我有的~~但是我只是不知道在该题中如何在只知道短期各厂商成本曲线的情况下去得出长期各厂商成本曲线……跪求啊~~拜托各位大人了~~中级微观对我这种刚接触经济学3个月的人来说还是难啊~~拜托牛人们写具体的步骤啊~~谢谢了~~~