[tex]\displaystyle \begin{cases}3n=-18\\ 3m-2n+4p=12\\2m-4n=16 \end{cases}\Rightarrow \begin{cases}n=-6\\ 3m+12+4p=12\\2m+24=16 \end{cases} \Rightarrow \\\\\Rightarrow \begin{cases}n=-6\\ -12+12+4p=12\\m=-4 \end{cases} \Rightarrow \begin{cases}n=-6\\ p=3\\m=-4 \end{cases}[/tex]
So, solution of the linear system is the following ordered triple [tex](-4,-6,3)[/tex]
