Combinatie
\(\left\{\begin{matrix}3x+4y=-43\\-7y+3x=1\end{matrix}\right.\)
\(\left\{\begin{matrix}3x+4y=-43\\-7y+3x=1\end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}3x+4y=-43\\3x-7y=1\end{matrix}\right.\text{(Niet verplichte stap, proper schrijven)}\\ \Leftrightarrow \left\{\begin{array}{c|c|c}3x+4y=-43& \color{red}{1.} & \color{blue}{7.} \\3x-7y=1& \color{red}{-1.} & \color{blue}{4.} \end{array}\right.\\ \Leftrightarrow \left\{\begin{matrix} \color{red}{\underline{3x-3x}+4y+7y=-43-1} \\ \color{blue}{21x+12x\underline{+28y-28y}=-301+4} \end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}11y=-44 \\33x=-297\end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}y=\frac{-44}{11}=-4 \\x=\frac{-297}{33}=-9\end{matrix}\right.\\ \qquad V=\{(-9,-4)\}\)