Determine (giving reasons for your answer) whether or

not the following subsets of

R3 are subspaces of R3:

(i) {(x, y, z) | xy = 0}

(ii) {(x, y, z) | x = 3z}

for (i) I got no, the set is not a subset of R3

for (ii) Yes, the set is a subset of R3

**Could someone please tell me if I'm right or not...?**

What is the

span of a set of vectors in Rn? Does the set of vectors

{(1, 2, 4), (2, 1, 3), (4,−1, 1)} span R3? Give reasons for your answer.

**Would someone be able to step through this problem for me please...?**