Let $A=\begin{bmatrix} a_{1} & a_{2} & a_{3} \end{bmatrix}$ and $3a_{1}+2a_{2}+a_{3}=0$ where $a_{i}$ are matrix columns. Find the nullspace of $A$.
So, my initial thought was that the nullspace is the span of the vector $\begin{bmatrix} 3\\ 2\\ 1 \end{bmatrix}$, but I'm not quite sure.