For the matrix $D$ below use the extended echelon form to find:
- A linearly independent set whose span is the column space of $D$.
- A linearly independent set whose span is the left null space of $D$.
\begin{align*}
D&=
\begin{bmatrix}
-7 & -11 & -19 & -15\\
6 & 10 & 18 & 14 \\
3 & 5 & 9 & 7 \\
-1 & -2 & -4 & -3
\end{bmatrix}
\end{align*}