Optellen geeft \(10a=-5\text{,}\) dus \(a=-\frac{1}{2}\text{.}\)

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

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

\(\begin{cases}a-b=-4 \\ 4a-2b=-4\end{cases}\) \(\begin{vmatrix}2 \\ 1\end{vmatrix}\) geeft \(\begin{cases}2a-2b=-8 \\ 4a-2b=-4\end{cases}\)

Aftrekken geeft \(-2a=-4\text{,}\) dus \(a=2\text{.}\)

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

De oplossing is \((a, b)=(2, 6)\text{.}\)

\(\begin{cases}4x+3y=-5 \\ 6x+5y=-5\end{cases}\) \(\begin{vmatrix}5 \\ 3\end{vmatrix}\) geeft \(\begin{cases}20x+15y=-25 \\ 18x+15y=-15\end{cases}\)

Aftrekken geeft \(2x=-10\text{,}\) dus \(x=-5\text{.}\)

\(\begin{rcases}4x+3y=-5 \\ x=-5\end{rcases}\begin{matrix}4⋅-5+3y=-5 \\ 3y=15 \\ y=5\end{matrix}\)

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

Gelijk stellen geeft \(8y+20=5y+14\)

\(3y=-6\) dus \(y=-2\)

\(\begin{rcases}x=8y+20 \\ y=-2\end{rcases}\begin{matrix}x=8⋅-2+20 \\ x=4\end{matrix}\)

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

Substitutie geeft \(4p+7(2p+14)=-10\)

Haakjes wegwerken geeft
\(4p+14p+98=-10\)
\(18p=-108\)
\(p=-6\)

\(\begin{rcases}q=2p+14 \\ p=-6\end{rcases}\begin{matrix}q=2⋅-6+14 \\ q=2\end{matrix}\)

De oplossing is \((p, q)=(-6, 2)\text{.}\)

Substitutie geeft \(y=4(7y+25)+8\)

Haakjes wegwerken geeft
\(y=28y+100+8\)
\(-27y=108\)
\(y=-4\)

\(\begin{rcases}x=7y+25 \\ y=-4\end{rcases}\begin{matrix}x=7⋅-4+25 \\ x=-3\end{matrix}\)

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