The method by which you arrive at an answer is as important as the answer itself. Therefore, a portion of your grade for the homework is based on showing your work. It is not sufficient to simply provide the answer. Further, if you make an assumption, clearly state it. 1. (20 points) Suppose X and Y are independent, identically distributed (iid) random variables with the common pdf ????(??)=exp(??)??(??) ????(??)=exp(??)??(??) a) Find the pdf of Z = X Y. b) Find the pdf of Z = X - Y