\begin{exercice}
Même consigne qu'à l'exercice \RefExercice{2G5_base_systeme_enonce}.
\vspace{1em}
\begin{colenumerate}{2}
\item {$\left\{\begin{array}{l}
                 3y+6x=-3\\
                 2y-4x=6
             \end{array}\right.$ }
\item {$\left\{\begin{array}{l}
                 y=2x+3\\
                 x=-3x-4
             \end{array}\right.$}
\item {$\left\{\begin{array}{l}
                 y=3x-5\\
                 2y-6x=4
             \end{array}\right.$}
\item {$\left\{\begin{array}{l}
                 y=\dfrac{\TopStrut 1}{\BotStrut 3}x-2\\
                 x=4
             \end{array}\right.$}
\end{colenumerate}
\end{exercice}
