This is LaTeX code:

[latex]
\left[\begin{array}{c}
x \\ y \\ z
\end{array}\right] = \left[\begin{array}{c}
4 \\ 0 \\ -6
\end{array}\right] + t \left[\begin{array}{c}
-7 \\ 1 \\ 9
\end{array}\right]
[/latex]