In the form a(x-h)^2+k, the vertex is (h, k), so the vertex is (25, 361). This means that the studio makes the most profit from selling 25 memberships, and thus makes 361 dollars.
B. The x-intercepts are the values of x for which f(x) is 0. This equation can be factored as (-a+6)(a-44)=0, with solutions 6 and 44. Therefore, by selling either 6 memberships or 44 memberships, the studio breaks even, neither making nor losing money.