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

\(\begin{rcases}4a-3b=-1 \\ a=-4\end{rcases}\begin{matrix}4⋅-4-3b=-1 \\ -3b=15 \\ b=-5\end{matrix}\)

De oplossing is \((a, b)=(-4, -5)\text{.}\)

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

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

\(\begin{rcases}2x+2y=-4 \\ y=7\end{rcases}\begin{matrix}2x+2⋅7=-4 \\ 2x=-18 \\ x=-9\end{matrix}\)

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

\(\begin{cases}5p+3q=-3 \\ 2p-2q=-6\end{cases}\) \(\begin{vmatrix}2 \\ 3\end{vmatrix}\) geeft \(\begin{cases}10p+6q=-6 \\ 6p-6q=-18\end{cases}\)

Optellen geeft \(16p=-24\text{,}\) dus \(p=-1\frac{1}{2}\text{.}\)

\(\begin{rcases}5p+3q=-3 \\ p=-1\frac{1}{2}\end{rcases}\begin{matrix}5⋅-1\frac{1}{2}+3q=-3 \\ 3q=4\frac{1}{2} \\ q=1\frac{1}{2}\end{matrix}\)

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

Gelijk stellen geeft \(6x+33=8x+43\)

\(-2x=10\) dus \(x=-5\)

\(\begin{rcases}y=6x+33 \\ x=-5\end{rcases}\begin{matrix}y=6⋅-5+33 \\ y=3\end{matrix}\)

De oplossing is \((x, y)=(-5, 3)\text{.}\)

Substitutie geeft \(7(6y+35)+3y=20\)

Haakjes wegwerken geeft
\(42y+245+3y=20\)
\(45y=-225\)
\(y=-5\)

\(\begin{rcases}x=6y+35 \\ y=-5\end{rcases}\begin{matrix}x=6⋅-5+35 \\ x=5\end{matrix}\)

De oplossing is \((x, y)=(5, -5)\text{.}\)

Substitutie geeft \(a=9(7a+41)+3\)

Haakjes wegwerken geeft
\(a=63a+369+3\)
\(-62a=372\)
\(a=-6\)

\(\begin{rcases}b=7a+41 \\ a=-6\end{rcases}\begin{matrix}b=7⋅-6+41 \\ b=-1\end{matrix}\)

De oplossing is \((a, b)=(-6, -1)\text{.}\)