Answer :
Using the profit concept, we have that:
- The expression is: P(x) = -0.5x² + 40x - 300.
- A profit of $300 is found with x = 20 and x = 60.
What is the profit concept?
Profit is given by revenue subtracted by costs.
In this problem, we have that:
- The revenue is: R(x) = 90x - 0.5x².
- The costs are: C(x) = 50x + 300.
Hence the expression for the profit is given as follows:
P(x) = R(x) - C(x)
P(x) = 90x - 0.5x² - 50x - 300
P(x) = -0.5x² + 40x - 300.
A profit of $300 is found when P(x) = 300, hence:
300 = -0.5x² + 40x - 300
0.5x² - 40x + 600 = 0.
x² - 80x + 1200 = 0.
(x - 60)(x - 20) = 0.
Hence the values are:
- x - 60 = 0 -> x = 60.
- x - 20 = 0 -> x = 20.
More can be learned about the profit concept at https://brainly.com/question/4001746
#SPJ1