Inverse Matrix/3x3/4/Aufgabe/Lösung

${}{\begin{pmatrix}1&1&0\\2&3&1\\0&0&7\end{pmatrix}}$	${}{\begin{pmatrix}1&0&0\\0&1&0\\0&0&1\end{pmatrix}}$
${}{\begin{pmatrix}1&1&0\\0&1&1\\0&0&7\end{pmatrix}}$	${}{\begin{pmatrix}1&0&0\\-2&1&0\\0&0&1\end{pmatrix}}$
${}{\begin{pmatrix}1&1&0\\0&1&1\\0&0&1\end{pmatrix}}$	${}{\begin{pmatrix}1&0&0\\-2&1&0\\0&0&{\frac {1}{7}}\end{pmatrix}}$
${}{\begin{pmatrix}1&1&0\\0&1&0\\0&0&1\end{pmatrix}}$	${}{\begin{pmatrix}1&0&0\\-2&1&-{\frac {1}{7}}\\0&0&{\frac {1}{7}}\end{pmatrix}}$
${}{\begin{pmatrix}1&0&0\\0&1&0\\0&0&1\end{pmatrix}}$	${}{\begin{pmatrix}3&-1&{\frac {1}{7}}\\-2&1&-{\frac {1}{7}}\\0&0&{\frac {1}{7}}\end{pmatrix}}$

Zur gelösten Aufgabe