Answer: The function's formula would be 

Explanation:
Since we have given that 
Price of each ticket = $70
Number of tickets = 10
Total cost price of tickets would be 

After selling 10 tickets, there is a net loss of $800.
So, Total product cost would be 

We need to write the function's formula for the number of tickets sold 'n'.
So, the function's formula would be 
