Given the demand and supply model as follows: = + , > 0, < 0 and = + , < 0, > 0. Solve for the equilibrium of the model. (4 marks) II. Suppose now, the supplier must pay an excise tax of RMt per unit, then the quantity supplied will depend not on the selling price, but on the selling price after tax, write the new supply equation. (2 marks) III. Now, determine the equilibrium of the model. (4 marks) IV. Compare the finding in i. and iii. and provide some comments. (5 marks)