Aftrekken geeft \(-a = 6 \text{,}\) dus \(a = -6 \text{.}\)

\(\begin{rcases}2 a - b = 4 \\ a = -6\end{rcases} \begin{matrix}2 ⋅ -6 - b = 4 \\ -b = 16 \\ b = -16\end{matrix}\)

De oplossing is \((a , b) = (-6 , -16) \text{.}\)

\(\begin{cases}6 a - 4 b = 4 \\ a + 2 b = 6\end{cases}\) \(\begin{vmatrix}1 \\ 2\end{vmatrix}\) geeft \(\begin{cases}6 a - 4 b = 4 \\ 2 a + 4 b = 12\end{cases}\)

Optellen geeft \(8 a = 16 \text{,}\) dus \(a = 2 \text{.}\)

\(\begin{rcases}6 a - 4 b = 4 \\ a = 2\end{rcases} \begin{matrix}6 ⋅ 2 - 4 b = 4 \\ -4 b = -8 \\ b = 2\end{matrix}\)

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

\(\begin{cases}4 x + 6 y = -5 \\ 3 x + 5 y = -6\end{cases}\) \(\begin{vmatrix}5 \\ 6\end{vmatrix}\) geeft \(\begin{cases}20 x + 30 y = -25 \\ 18 x + 30 y = -36\end{cases}\)

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

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

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

Gelijk stellen geeft \(8 x - 38 = 6 x - 28\)

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

\(\begin{rcases}y = 8 x - 38 \\ x = 5\end{rcases} \begin{matrix}y = 8 ⋅ 5 - 38 \\ y = 2\end{matrix}\)

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

Substitutie geeft \(9 p + 5 (3 p - 6) = 66\)

Haakjes wegwerken geeft
\(9 p + 15 p - 30 = 66\)
\(24 p = 96\)
\(p = 4\)

\(\begin{rcases}q = 3 p - 6 \\ p = 4\end{rcases} \begin{matrix}q = 3 ⋅ 4 - 6 \\ q = 6\end{matrix}\)

De oplossing is \((p , q) = (4 , 6) \text{.}\)

Substitutie geeft \(x = 6 (2 x + 14) - 40\)

Haakjes wegwerken geeft
\(x = 12 x + 84 - 40\)
\(-11 x = 44\)
\(x = -4\)

\(\begin{rcases}y = 2 x + 14 \\ x = -4\end{rcases} \begin{matrix}y = 2 ⋅ -4 + 14 \\ y = 6\end{matrix}\)

De oplossing is \((x , y) = (-4 , 6) \text{.}\)