Acharity organization had a fundraiser where each ticket was sold for a fixed price of $ 70. they had to sell a few tickets just to cover necessary production costs. after selling 10 tickets, they were still at a net loss of $800, (due to the production costs). let (n)p, denote the net profit from the fundraiser p (measured in dollars) as a function of the number of tickets sold n. write the function's formula.