A)
The vertex can be determined using the completing square method.
f(x) = -(x² - 44x + 384)
= -(x² - 44x + 384 + 22² - 22²)
= -(x - 22)² - 384 + 22²
= -(x - 22)² + 100
The vertex is (22 , 100) and this means that the maximum profit(due to negative sign of coefficient of x) is $100 and is achieved when 22 combos are sold
B) 0 = -(x - 22)² + 100
x - 22 = 10
x = 32
x - 22 = -10
x = 12
This means the shop gains no profit when it sells 32 or 12 combos, and this can be due to the production cost being equal to the money gained via sales.
Gravity simply does not allow that