\begin{exercice*} \ExerciceRefMethode{2G5_M_lireequationdedroite}\\
\label{2G5_E_lireequationdedroite}
Déterminer une  équation de chacune des droites tracées dans le repère ci-dessous.
\begin{center}
\begin{tikzpicture}[general, scale=0.85]
\draw [quadrillage](-4,-3) grid (5,3);
\axeX{-4}{5}{-3,-2,-1,1,2,3,4}
\axeY{-3}{3}{-2,-1,1,2}
\origine
\draw [epais,color=H1] (3,-3) -- (3,3);
\draw [epais,color=J1] (-4,-1)--(5,-1);
\draw [epais,color=F1] (-2,-3)--(1,3);
\draw [epais,color=G1] (-0.333,3)--(1.667,-3);
\draw[color=H1] (3.37,2.53) node {{\boldmath ${\cal D}_2$}};
\draw[color=J1] (-2.61,-1.4) node {{\boldmath ${\cal D}_1$}};
\draw[color=F1] (1.3,2.6) node {{\boldmath ${\cal D}_3$}};
\draw[color=G1] (-0.5,2.69) node {{\boldmath ${\cal D}_4$}};
\end{tikzpicture}
 \end{center}
 \begin{corrige}
~\\
\begin{enumerate}
\item $D_1:y=-1$ \item $D_2: x=3$ \item $D_3: y=2x+1$ \item $D_4: y=-3x+2$ 
\end{enumerate}
\end{corrige}
 \end{exercice*}
 
 
