$2 x+3 y-z=0$
$x-y-2 z=0$
$3 x+y+3 z=0$
The given system of homogeneous equations can be written in matrix form as follows:
$\left[\begin{array}{ccc}2 & 3 & -1 \\ 1 & -1 & -2 \\ 3 & 1 & 3\end{array}\right]\left[\begin{array}{l}x \\ y \\ z\end{array}\right]=\left[\begin{array}{l}0 \\ 0 \\ 0\end{array}\right]$
$A X=O$
Here,
$A=\left[\begin{array}{ccc}2 & 3 & -1 \\ 1 & -1 & -2 \\ 3 & 1 & 3\end{array}\right], X=\left[\begin{array}{l}x \\ y \\ z\end{array}\right]$ and $O=\left[\begin{array}{l}0 \\ 0 \\ 0\end{array}\right]$
Now,
$|A|=\left|\begin{array}{ccc}2 & 3 & -1 \\ 1 & -1 & -2 \\ 3 & 1 & 3\end{array}\right|$
$=2(-3+2)-3(3+6)-1(1+3)$
$=-2-27-4$
$=-33 \neq 0$
So, the given system of homogeneous equations has only trivial solution, which is given below:
$x=y=z=0$