The demand equation for an item is p = p(x) = 60 - 100 X, where p is the price in dollars and x is the number of units (in thousands) made. (Use symbolic notation and fractions where needed.) (a) Assuming all units made can be sold, find the revenue function R(x) = xp(x). R(X) = (b) Marginal revenue is defined as the additional revenue earned by selling an additional unit. If R'(x) is used to measure the marginal revenue, find the marginal revenue when 1 million units are sold. (Give your answer as a whole or exact number.) R' (1000) = dollars/(thousand units)Find an equation of the tangent line to the graph of function f(x) = > at the point (-4, 16) . (Use symbolic notation and fractions where needed. Let y = f(x) and express equation in terms of y and x.) equation