Answer: The equation that could be used to represent this situation is:
R(x) = (100 + 20n)(125 - 10n)
where x is the price per cleaning, n is the number of times the price is reduced by $10, and R(x) is the total revenue.
Initially, the price is $125 and there are 100 customers, so the revenue is:
R(125) = 100(125) = 12500
If the price is reduced by $10, the new price is $115, and the number of customers increases by 20:
R(115) = (100 + 20)(115) = 13800
Continuing in this way, the revenue for each price reduction can be calculated. The total revenue is the sum of all the revenues:
R(x) = (100 + 20n)(125 - 10n)
R(x) = 12500 + 2000n - 1000n^2
Simplifying this equation, we get:
R(x) = -1000n^2 + 1000n + 12500
Therefore, the correct equation to represent this situation is:
R(x) = -2x^2 + 350x.
Explanation: