[tex]\displaystyle\\\begin{cases} -x+18y=8 \\ 3x+6y=6|:3 \end{cases} \Leftrightarrow \begin{cases} -x+18y=8\\x+2y=2\end{cases}.\\Prin~adunare~obtinem~:~20y=10 \implies \boxed{y=\frac{1}{2}},~de~unde~prin~inlocuire\\intr-una~dintre~relatiile~de~mai~sus~obtinem~\boxed{x=1}.[/tex]