Please help me answer the following questions:

Question 1: The revenue agency outlines the following tax schedule: If a person earns up to $2000, then he is taxed at 5%. The next $10,000 will be taxed at 10%. Any additional income is taxed at 25%. Let Tdenote tax, and l denote income. a) Derive Marginal Tax Function and draw the corresponding graph. (2 marks) b) Derive Tax Function and draw the corresponding graph. (4 marks) c) Show that the marginal tax function is not continuous at |=2000. (2 marks) d) Show that the tax function is continuous at |=2000, but not differentiable. (2 marks) Question 2: Suppose that the production function is Q(L) = E, where L is the labor used in production. Let p be the prices, and w be the wages that the firm pays. Write down the profit function, and obtain the optimal labor, L* as a function of p and w. (5 marks) Question 3: Solve the following systems of equations using gaussian elimination. Other methods used will not receive any credits. (5 marks) x+2y=3 5x+4y=13