I just need to know how to start this... I'm looking through my notes but can't figure out how to begin. The wording is also a little bit confusing.

Find a finite subset of each of the following subspaces for which the subspace is the span of the subset.

{x bar is an element of R^{3}such that A(x bar) = theta bar} where A=

1 1 2 1 -1 and theta bar is the zero vector in R^{3}.

2 2 1 2 -1

3 3 2 3 -1