Aftrekken geeft \(-3 b = 6 \text{,}\) dus \(b = -2 \text{.}\)

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

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

\(\begin{cases}6 x - 3 y = -3 \\ 4 x - y = 6\end{cases}\) \(\begin{vmatrix}1 \\ 3\end{vmatrix}\) geeft \(\begin{cases}6 x - 3 y = -3 \\ 12 x - 3 y = 18\end{cases}\)

Aftrekken geeft \(-6 x = -21 \text{,}\) dus \(x = 3\frac{1}{2} \text{.}\)

\(\begin{rcases}6 x - 3 y = -3 \\ x = 3\frac{1}{2}\end{rcases} \begin{matrix}6 ⋅ 3\frac{1}{2} - 3 y = -3 \\ -3 y = -24 \\ y = 8\end{matrix}\)

De oplossing is \((x , y) = (3\frac{1}{2} , 8) \text{.}\)

\(\begin{cases}5 x + 5 y = 5 \\ 4 x - 6 y = -1\end{cases}\) \(\begin{vmatrix}6 \\ 5\end{vmatrix}\) geeft \(\begin{cases}30 x + 30 y = 30 \\ 20 x - 30 y = -5\end{cases}\)

Optellen geeft \(50 x = 25 \text{,}\) dus \(x = \frac{1}{2} \text{.}\)

\(\begin{rcases}5 x + 5 y = 5 \\ x = \frac{1}{2}\end{rcases} \begin{matrix}5 ⋅ \frac{1}{2} + 5 y = 5 \\ 5 y = 2\frac{1}{2} \\ y = \frac{1}{2}\end{matrix}\)

De oplossing is \((x , y) = (\frac{1}{2} , \frac{1}{2}) \text{.}\)