The first integral in the table matches the form in the problem, with
... u = x, a = 2, b = 5.
Then the profit function is
... p(x) = 2(15x-4)/(375)√((2+5x)³) - 1501.09
(Without the added constant, the function p(1) evaluates to about 1.09.)
A graph shows the number of sales required for a $12000 profit is about 47 cars.
Sale of 75 cars per week will result in a profit of about p(75) ≈ $42,263.