14. The average cost and average revenue functions for a particular brand of mobile phone are given by the equation. 8000 AC =15+ and AR - 25 Q a. Write down the equations for the TR. TC, MR, MC b. How many mobile phones must be made and sold to break even? c. Write down the equation of the profit function. 11. Find the A-! and A" for the following matrix A2x2 A = 12 31