Combinatie
\(\left\{\begin{matrix}-9x+3y=3\\3x=-5y-31\end{matrix}\right.\)
\(\left\{\begin{matrix}-9x+3y=3\\3x=-5y-31\end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}-9x+3y=3\\3x+5y=-31\end{matrix}\right.\text{(Niet verplichte stap, proper schrijven)}\\ \Leftrightarrow \left\{\begin{array}{c|c|c}-9x+3y=3& \color{red}{1.} & \color{blue}{5.} \\3x+5y=-31& \color{red}{3.} & \color{blue}{-3.} \end{array}\right.\\ \Leftrightarrow \left\{\begin{matrix} \color{red}{\underline{-9x+9x}+3y+15y=3-93} \\ \color{blue}{-45x-9x\underline{+15y-15y}=15+93} \end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}18y=-90 \\-54x=108\end{matrix}\right.\\ \Leftrightarrow \left\{\begin{matrix}y=\frac{-90}{18}=-5 \\x=\frac{108}{-54}=-2\end{matrix}\right.\\ \qquad V=\{(-2,-5)\}\)