Can somebody help me on this

30 Consider a firm whose production function is given by the Cobb-Douglas function y = zKa N1-a where z is is productivity, K is the fixed amount of capital available to the firm, N is labor, and a E (0, 1) is a constant. a. Show mathematically that this production function exhibits constant returns to scale. b. We define the labor share as the part of output paid out to labor: labor share = wN/y, where w is the real wage. Solve the firm's optimization problem, and then use that to show that the labor share equals 1-a. c. Write a short paragraph discussing what has been happening to the labor share in U.S. data in recent decades and why. Now suppose that a technological innovation increases the firm's productivity by 10%. d. Show how this change affects output in the diagram that relates the firm's output to the amount of labor it employs. Derive mathematically the resulting change in the marginal product of labor. e. At the given wage rate, explain whether the firm's demand for labor will increase, decrease, or remain the same in response to this innovation