Hi,
Annual profit in thousands of dollars is given by the function,
P(x) = -.1x2 + 50x - 300, where x is the number of items sold, x ≥ 0.
the -300 would be the adjustments to the annual profits due to 'fixed cost'
that is to say if NO items were sold..there would be a loss of $300,000
and...solving -1x^2 + 50x - 300 = 0 would tell us how many need to be sold
to break even.