Final answer:
The monthly revenue of the online shopping club can be represented by the function R(x) = (12,000 - (400 * x)) * (9 + x), where x is the price increase.
Step-by-step explanation:
The monthly revenue received by the club can be calculated by multiplying the number of members by the monthly fee.
Let's break down the steps to create the function R:
First, we know that the initial membership fee is $9 and the number of members is 12,000.
So the initial monthly revenue is $9 * 12,000 = $108,000.
Next, we need to account for the decrease in membership for each $1 increase in fee.
We know that for each $1 increase, the club loses approximately 400 members.
So if the fee increases by x dollars, the number of members remaining is 12,000 - (400 * x).
Finally, we can calculate the new monthly revenue R by multiplying the remaining number of members by the new fee (9 + x).
So the function R is equal to R(x) = (12,000 - (400 * x)) * (9 + x).