Good day, Please help me with this Statistics problem

9. Ex 9.85 Let Y1, Y2, ..., Y, denote a random sample from the density function given by f(y |a, 0) = (@)ga ) y-e-x/, y > 0, elsewhere, where a > 0 is known. a Find the MLE 0 of 0. b Find the expected value and variance of 0. (5)5. Let Y1, Y2. ..., Y, denote independent and identically distributed random variables from a power family distribution with parameters a and 0 = 3. Then, as in Exercise 9.43, if a > 0, f(yla) = Jay-1/3", Osys3, lo, elsewhere. Show that E(Y1) = 30/(a + 1) and derive the method-of-moments estimator for a. Also determine if the estimator is unbiased for a. (6)