Step-by-step explanation:
Given;
We are given the revenue and cost function of a car wash facility as follows;

Also, we are told that in this function, x represents the number of cars washed.
Required;
We are required to calculate the profit when 10 cars are washed.
Step-by-step solution;
To begin, we will take note that the profit function is given as;

Therefore, to determine the profit at any level of input x, we would have;

We now substitute the values given;


Notice how the negative sign is distributed among the two values in the right parenthesis.

We can now determine the profit when 10 cars are washed, that is, when x = 10.




ANSWER:
The profit from washing 10 cars therefore will be $31.5