Your function is off . . . but you were close.
In planning a restaurant, it is estimated that a profit of $6 per seat will be made
if the number of seats is no more than 50, inclusive.
On the other hand, the profit on each seat will decrease by 10¢ for each seat above 50.
a) Find the number of seats that will produce the maximum profit.
Let = number of seats in excess of 50.
There will be: . seats.
Then each seat brings a profit of: . dollars.