3. (10 points) Let 1 1 2 2 A : 0 3 3 0 2 1 1 4 Determine the nullity and rank of A and justify your answer by giving a basis for either (not necessarily both) N(A) or R(A). 4. (10 points) Let p : (1,2,1),q : (3,4,5),r : (7,1,0). Determine whether each of the following subsets W C R3 is a subspace, and justify your answer. (Hint: Remember that 112 ||v :v'v). (a) W: {\"116 R3 = Huipll : Huiqll} (b) W = {u E R3 : llu 97H = llu T'll}