Problem 3. (8+4 points) Suppose that V, WC R4 are two subspaces such that V = span{(1, 2, -1,3), (1, -2,-1,2)}, W = span{(-1, -3, -2, -1), (1, 1, 0, 2)}.

1. By general theory, we know that there must exist a (not necessarily unique) finite set SCR4 such that VnW = span(S). Find such a set S. 2. Is the union VUW a subspace of R4 as well? Justify your answer with reason.