Aftrekken geeft \(y = 7 \text{.}\)

\(\begin{rcases}4 x + 6 y = 6 \\ y = 7\end{rcases} \begin{matrix}4 x + 6 ⋅ 7 = 6 \\ 4 x = -36 \\ x = -9\end{matrix}\)

De oplossing is \((x , y) = (-9 , 7) \text{.}\)

\(\begin{cases}5 x - 4 y = -4 \\ 2 x - 2 y = 6\end{cases}\) \(\begin{vmatrix}1 \\ 2\end{vmatrix}\) geeft \(\begin{cases}5 x - 4 y = -4 \\ 4 x - 4 y = 12\end{cases}\)

Aftrekken geeft \(x = -16 \text{.}\)

\(\begin{rcases}5 x - 4 y = -4 \\ x = -16\end{rcases} \begin{matrix}5 ⋅ -16 - 4 y = -4 \\ -4 y = 76 \\ y = -19\end{matrix}\)

De oplossing is \((x , y) = (-16 , -19) \text{.}\)

\(\begin{cases}3 a + 5 b = -1 \\ 4 a - 4 b = 4\end{cases}\) \(\begin{vmatrix}4 \\ 5\end{vmatrix}\) geeft \(\begin{cases}12 a + 20 b = -4 \\ 20 a - 20 b = 20\end{cases}\)

Optellen geeft \(32 a = 16 \text{,}\) dus \(a = \frac{1}{2} \text{.}\)

\(\begin{rcases}3 a + 5 b = -1 \\ a = \frac{1}{2}\end{rcases} \begin{matrix}3 ⋅ \frac{1}{2} + 5 b = -1 \\ 5 b = -2\frac{1}{2} \\ b = -\frac{1}{2}\end{matrix}\)

De oplossing is \((a , b) = (\frac{1}{2} , -\frac{1}{2}) \text{.}\)