"Let A = \begin{pmatrix}-1&2&-13&-6\\ 2&1&1&-3\\ -3&0&-9&0\\ 7&2&11&-6\end{pmatrix}

Determine a basis for the null space of A."

So I reduced it and got the following matrix:

\begin{pmatrix}1&0&3&0\\ 0&1&-5&-3\\ 0&0&0&0\\ 0&0&0&0\end{pmatrix}

Writing it in terms of parameters I got:

x1 = -3x3

x2 = 5x3 + 3x4

So I thought the vectors were:

\begin{pmatrix}-3\\ 5\\ 0\\ 0\end{pmatrix} and \begin{pmatrix}0\\ 3\\ 0\\ 0\end{pmatrix}

But this incorrect.

Any help?

## Bookmarks