Need help with 5 and 6 please

Question 5 Suppose a company's revenue function is given by R(q) = -q3 + 390q2 and its cost function is given by C(q) = 480 + 15q, where q is hundreds of units sold/produced, while R(q) and C(q) are in total dollars of revenue and cost, respectively. A) Find a simplified expression for the marginal profit function. (Be sure to use the proper variable in your answer.) MP(q) : B) How many items (in hundreds) need to be sold to maximize profits? Answer: hundred units must be sold. (Round to two decimal places.) Question Help: DVideo Submit Question Question 6 0/10 pts 9 5 99 0 Deta For the given cost function C(x) = 19600 + 500x + x find: a) The cost at the production level 1050 b) The average cost at the production level 1050 c) The marginal cost at the production level 1050 d) The production level that will minimize the average cost e) The minimal average cost Question Help: Video Submit