Could you please solve it step by step with clear explanation? Please do not only write the answer. Explanation is very important.

Could you please explain it with clear step by step solution? Please, do not write only answer. (b) (10 points) Consider the following Optimization problem: 2 = f($la$2) subject to 9(31, 3:2) = c, I have attached the question below. Where c is a constant. Write the Lagrangian L for this problem. Show that at the optimum: dz." / dc = X' where A denotes the Lagrange multiplier. Based on this result, what is the interpre- tation of the )l