Algebra-Lineares Gleichungssystem-Additionsverfahren (2)
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Beispiel Nr: 11
$\begin{array}{l}
\text{Gegeben:} \\
a1 \cdot x +b1 \cdot y =c1\\
a2 \cdot x +b2 \cdot y =c2 \\
\\ \text{Gesucht:} \\\text{x und y}
\\ \\ \textbf{Gegeben:} \\
\\
1\frac{1}{5} x -1\frac{1}{3} y =5\frac{1}{3}\\
2\frac{1}{2} x -\frac{1}{4} y = 12\frac{3}{8} \\
\\
\\ \\ \textbf{Rechnung:} \\\begin{array}{l|l}
\begin{array}{l}
\\I \qquad 1\frac{1}{5} x -1\frac{1}{3} y =5\frac{1}{3}\\
II \qquad 2\frac{1}{2} x -\frac{1}{4} y = 12\frac{3}{8} \\
I \qquad 1\frac{1}{5} x -1\frac{1}{3} y =5\frac{1}{3} \qquad / \cdot2\frac{1}{2}\\
II \qquad 2\frac{1}{2} x -\frac{1}{4} y = 12\frac{3}{8} \qquad / \cdot\left(-1\frac{1}{5}\right)\\
I \qquad 3 x -3\frac{1}{3} y =13\frac{1}{3}\\
II \qquad -3 x +\frac{3}{10} y = -14\frac{17}{20} \\
\text{I + II}\\
I \qquad 3 x -3 x-3\frac{1}{3} y +\frac{3}{10} y =13\frac{1}{3} -14\frac{17}{20}\\
-3\frac{1}{30} y = -1\frac{31}{60} \qquad /:\left(-3\frac{1}{30}\right) \\
y = \frac{-1\frac{31}{60}}{-3\frac{1}{30}} \\
y=\frac{1}{2} \\
\text{y in I}\\
I \qquad 1\frac{1}{5} x -1\frac{1}{3}\cdot \frac{1}{2} =5\frac{1}{3} \\
1\frac{1}{5} x -\frac{2}{3} =5\frac{1}{3} \qquad / +\frac{2}{3} \\
1\frac{1}{5} x =5\frac{1}{3} +\frac{2}{3} \\
1\frac{1}{5} x =6 \qquad / :1\frac{1}{5} \\
x = \frac{6}{1\frac{1}{5}} \\
x=5 \\
L=\{5/\frac{1}{2}\}
\end{array} &
\begin{array}{l}
\\I \qquad 1\frac{1}{5} x -1\frac{1}{3} y =5\frac{1}{3}\\
II \qquad 2\frac{1}{2} x -\frac{1}{4} y = 12\frac{3}{8} \\
I \qquad 1\frac{1}{5} x -1\frac{1}{3} y =5\frac{1}{3} \qquad / \cdot\left(-\frac{1}{4}\right)\\
II \qquad 2\frac{1}{2} x -\frac{1}{4} y = 12\frac{3}{8} \qquad / \cdot1\frac{1}{3}\\
I \qquad -\frac{3}{10} x +\frac{1}{3} y =-1\frac{1}{3}\\
II \qquad 3\frac{1}{3} x -\frac{1}{3} y = 16\frac{1}{2} \\
\text{I + II}\\
I \qquad -\frac{3}{10} x +3\frac{1}{3} x+\frac{1}{3} y -\frac{1}{3} y =-1\frac{1}{3} +16\frac{1}{2}\\
3\frac{1}{30} x = 15\frac{1}{6} \qquad /:3\frac{1}{30} \\
x = \frac{15\frac{1}{6}}{3\frac{1}{30}} \\
x=5 \\
\text{x in I}\\
I \qquad 1\frac{1}{5} \cdot 5 -1\frac{1}{3}y =5\frac{1}{3} \\
-1\frac{1}{3} y +6 =5\frac{1}{3} \qquad / -6 \\
-1\frac{1}{3} y =5\frac{1}{3} -6 \\
-1\frac{1}{3} y =-\frac{2}{3} \qquad / :\left(-1\frac{1}{3}\right) \\
y = \frac{-\frac{2}{3}}{-1\frac{1}{3}} \\
y=\frac{1}{2} \\
L=\{5/\frac{1}{2}\} \end{array}
\end{array}
\end{array}$