Please solve on paper showing all steps so I can follow along and learn

3. (20 points) The demand equation of a good is P + Q = 30, and the total cost function is 1 TC = E Q2 + 60 + 7 Write down the expression in terms of Q for total revenue. Find the level of output that maximizes total revenue. Write down the expression for prot. Find the level of output that maximizes prot. Verify that, at this value of Q, MR = MC. 9.0.57? 4. (20 points) For the following production function Q = K 2/31)\" , calculate, i) Marginal product labor, MPL: ii) Marginal product Capital, MPK: iii ) Identify if the returns to scale is diminishing, increasing or constant? Note that the return to scale shows the change in Y due to a proportionate change in ALL factors of production