For the matrix $A$ below, find a linearly independent set $S$ so that the null space of $A$ is spanned by $S$, that is, $\nsp{A}=\spn{S}$. \begin{equation*} A= \begin{bmatrix} -1 & -2 & 2 & 1 & 5 \\ 1 & 2 & 1 & 1 & 5 \\ 3 & 6 & 1 & 2 & 7 \\ 2 & 4 & 0 & 1 & 2 \end{bmatrix} \end{equation*}