!$ A = { \begin{pmatrix} 6\,\,\,0\\-3\,\,\,0\\9\,\,\,0 \end{pmatrix}} !$

!$ \left ( 6\,\,-3\,\,\,\,9 \right) !$

!$ A = { \begin{pmatrix} 6\,\,\,-3\,\,\,9\\0\,\,\,\,0\,\,\,\,0 \end{pmatrix}} !$

!$ A = { \begin{pmatrix}6\\-3\\9 \end{pmatrix}} !$

!$ A = { \begin{pmatrix} 6\,\,\,12\\-3\,\,\,6\\9\,\,\,18 \end{pmatrix}} !$