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\(\left\{\begin{matrix}3x+6y=-3\\-2x-y=11\end{matrix}\right.\)

\(\left\{\begin{matrix}3x+6y=-3\\-2x-y=11\end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}3x+6y=-3\\ -2x-11=y\end{matrix}\right.\text{(Afzonderen onbekende met coëff. 1)}\\ \Leftrightarrow \left\{\begin{matrix}3x+6\left(-2x-11\right)=-3\\y=-2x-11\end{matrix}\right.\text{(Substitutie!)}\\ \Leftrightarrow \left\{\begin{matrix}3x-12x-66=-3\\y=-2x-11\end{matrix}\right.\text{(Distributie)}\\ \Leftrightarrow \left\{\begin{matrix}-9x=-3+66=63\\y=-2x-11\end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}x = \frac{63}{-9} = -7 \\ y=-2x-11\end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}x = -7 \\ y=-2.(-7)-11=3\end{matrix}\right.\\ \qquad V=\{(-7,3)\}\)