Aftrekken geeft \(-a=4\text{,}\) dus \(a=-4\text{.}\)

\(\begin{rcases}a-6b=-1 \\ a=-4\end{rcases}\begin{matrix}-4-6b=-1 \\ -6b=3 \\ b=-\frac{1}{2}\end{matrix}\)

De oplossing is \((a, b)=(-4, -\frac{1}{2})\text{.}\)

\(\begin{cases}2x+y=6 \\ 5x-4y=2\end{cases}\) \(\begin{vmatrix}4 \\ 1\end{vmatrix}\) geeft \(\begin{cases}8x+4y=24 \\ 5x-4y=2\end{cases}\)

Optellen geeft \(13x=26\text{,}\) dus \(x=2\text{.}\)

\(\begin{rcases}2x+y=6 \\ x=2\end{rcases}\begin{matrix}2⋅2+y=6 \\ y=2\end{matrix}\)

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

\(\begin{cases}5p+2q=-5 \\ 3p+3q=6\end{cases}\) \(\begin{vmatrix}3 \\ 2\end{vmatrix}\) geeft \(\begin{cases}15p+6q=-15 \\ 6p+6q=12\end{cases}\)

Aftrekken geeft \(9p=-27\text{,}\) dus \(p=-3\text{.}\)

\(\begin{rcases}5p+2q=-5 \\ p=-3\end{rcases}\begin{matrix}5⋅-3+2q=-5 \\ 2q=10 \\ q=5\end{matrix}\)

De oplossing is \((p, q)=(-3, 5)\text{.}\)

Gelijk stellen geeft \(2y-1=8y-13\)

\(-6y=-12\) dus \(y=2\)

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

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

Substitutie geeft \(6(2y-6)+5y=32\)

Haakjes wegwerken geeft
\(12y-36+5y=32\)
\(17y=68\)
\(y=4\)

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

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

Substitutie geeft \(a=4(6a+9)-13\)

Haakjes wegwerken geeft
\(a=24a+36-13\)
\(-23a=23\)
\(a=-1\)

\(\begin{rcases}b=6a+9 \\ a=-1\end{rcases}\begin{matrix}b=6⋅-1+9 \\ b=3\end{matrix}\)

De oplossing is \((a, b)=(-1, 3)\text{.}\)