Final answer:
To find the total amount earned by both stores, you combine the functions f(x) and g(x) by adding them together. The resulting function P(x), which represents the total amount earned, is P(x) = -13x^2 + 453x + 540.
Step-by-step explanation:
The total amount earned by both new stores is represented by combining the two functions. This is done using addition:
P(x) = f(x) + g(x)
P(x) = (-5x^2 + 168x + 432) + (-8x^2 + 285x + 108)
To find P(x), we add the corresponding terms:
P(x) = (-5x^2 - 8x^2) + (168x + 285x) + (432 + 108)
P(x) = -13x^2 + 453x + 540
Therefore, the function that represents the total amount earned by both stores, P(x), is:
P(x) = -13x^2 + 453x + 540