The given polyn. is not in std. form. To answer this question, we need to perform the indicated operations (mult., addn., subtrn.) first and then arrange the terms of this poly in descending order by powers of x:
P(x) = x(160 - x) - (100x + 500)
When this work has been done, we get P(x) = 160x - x^2 - 100x - 500, or
P(x) = -x^2 + 60x - 500
So, you see, the last term is -500. This means that if x = 0, not only is there no profit, but the company is "in the hole" for $500.