A bus company will plan a group trip for groups of 10 or larger. If the group is exactly 10, the cost is $50 per person. The company offers to discount each person's ticket by $2 for each addition to the group above 10. The revenue for the bus company is given by: R(x) = (10 + x)(50 - 2x) where x is the number of additional people above 10. Find the marginal revenue function using the product rule.
