(1 point) A company manufactures a units of one item and y units of another. The total cost in dollars, C, of producing these two items is approximated by the function C=7x+5xy + 7y + 900. (a) If the production quota for the total number of items (both types combined) is 30, find the minimum production cost. cost = 5175 (b) Estimate the additional production cost or savings if the production quota is raised to 31 or lowered to 29. production cost or savings = 570 (1 point) Use Lagrange multipliers to find the maximum and minimum values of f(x, y) maximum = minimum = (For either value, enter DNE if there is no such value.) xy + 3yy, subject to the constraint x + y < 38.3333333333333