Aftrekken geeft \(-a=8\text{,}\) dus \(a=-8\text{.}\)

\(\begin{rcases}5a-2b=4 \\ a=-8\end{rcases}\begin{matrix}5⋅-8-2b=4 \\ -2b=44 \\ b=-22\end{matrix}\)

De oplossing is \((a, b)=(-8, -22)\text{.}\)

\(\begin{cases}6x-4y=5 \\ 3x-3y=-3\end{cases}\) \(\begin{vmatrix}1 \\ 2\end{vmatrix}\) geeft \(\begin{cases}6x-4y=5 \\ 6x-6y=-6\end{cases}\)

Aftrekken geeft \(2y=11\text{,}\) dus \(y=5\frac{1}{2}\text{.}\)

\(\begin{rcases}6x-4y=5 \\ y=5\frac{1}{2}\end{rcases}\begin{matrix}6x-4⋅5\frac{1}{2}=5 \\ 6x=27 \\ x=4\frac{1}{2}\end{matrix}\)

De oplossing is \((x, y)=(4\frac{1}{2}, 5\frac{1}{2})\text{.}\)

\(\begin{cases}4p+2q=1 \\ 5p-3q=4\end{cases}\) \(\begin{vmatrix}3 \\ 2\end{vmatrix}\) geeft \(\begin{cases}12p+6q=3 \\ 10p-6q=8\end{cases}\)

Optellen geeft \(22p=11\text{,}\) dus \(p=\frac{1}{2}\text{.}\)

\(\begin{rcases}4p+2q=1 \\ p=\frac{1}{2}\end{rcases}\begin{matrix}4⋅\frac{1}{2}+2q=1 \\ 2q=-1 \\ q=-\frac{1}{2}\end{matrix}\)

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