Answer:

Step-by-step explanation:
Given that ;
The total cost for 100 firms is TC :

The marginal cost of one firm will be:



So; Now , the marginal cost for the all 100 firms is

The total cost for 60 firms is

The marginal cost of one firm will be:


The marginal cost for all the 60 firms will now be:



Finally; the long run supply function is industry supply function and which is therefore determined as :


