A company manufactures 2 models of MP3 players. Let x represent the number (in millions) of the first model made, and let y represent the number (in millions) of the second model made. The company's revenue can be modeled by the equation 2x - 4y - xy R(x, y) 150x + 50y - 2x Find the marginal revenue equations R(x, y) = Ry(x, y) = We can acheive maximum revenue when both partial derivatives are equal to zero. Set R = 0 and Ry = 0 and solve as a system of equations to the find the production levels that will maximize revenue. The "D test" will confirm if the critical point is a maximum or minimum. = Revenue will be maximized when: X = y =