Optellen geeft \(4 a = 2 \text{,}\) 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 \((a , b) = (\frac{1}{2} , \frac{1}{2}) \text{.}\)

\(\begin{cases}x - 4 y = -4 \\ 2 x - 2 y = -5\end{cases}\) \(\begin{vmatrix}1 \\ 2\end{vmatrix}\) geeft \(\begin{cases}x - 4 y = -4 \\ 4 x - 4 y = -10\end{cases}\)

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

\(\begin{rcases}x - 4 y = -4 \\ x = -2\end{rcases} \begin{matrix}-2 - 4 y = -4 \\ -4 y = -2 \\ y = \frac{1}{2}\end{matrix}\)

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

\(\begin{cases}4 x + 2 y = -4 \\ 5 x + 3 y = -3\end{cases}\) \(\begin{vmatrix}3 \\ 2\end{vmatrix}\) geeft \(\begin{cases}12 x + 6 y = -12 \\ 10 x + 6 y = -6\end{cases}\)

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

\(\begin{rcases}4 x + 2 y = -4 \\ x = -3\end{rcases} \begin{matrix}4 ⋅ -3 + 2 y = -4 \\ 2 y = 8 \\ y = 4\end{matrix}\)

De oplossing is \((x , y) = (-3 , 4) \text{.}\)