Inverse Matrix/3x3/1/Aufgabe/Lösung

${}{\begin{pmatrix}1&2&0\\4&2&1\\0&0&3\end{pmatrix}}$	${}{\begin{pmatrix}1&0&0\\0&1&0\\0&0&1\end{pmatrix}}$
${}{\begin{pmatrix}1&0&0\\4&2&1\\0&0&1\end{pmatrix}}$	${}{\begin{pmatrix}-{\frac {1}{3}}&{\frac {1}{3}}&-{\frac {1}{9}}\\0&1&0\\0&0&{\frac {1}{3}}\end{pmatrix}}$
${}{\begin{pmatrix}1&0&0\\0&2&1\\0&0&1\end{pmatrix}}$	${}{\begin{pmatrix}-{\frac {1}{3}}&{\frac {1}{3}}&-{\frac {1}{9}}\\{\frac {4}{3}}&-{\frac {1}{3}}&{\frac {4}{9}}\\0&0&{\frac {1}{3}}\end{pmatrix}}$
${}{\begin{pmatrix}1&0&0\\0&2&0\\0&0&1\end{pmatrix}}$	${}{\begin{pmatrix}-{\frac {1}{3}}&{\frac {1}{3}}&-{\frac {1}{9}}\\{\frac {4}{3}}&-{\frac {1}{3}}&{\frac {1}{9}}\\0&0&{\frac {1}{3}}\end{pmatrix}}$
${}{\begin{pmatrix}1&0&0\\0&1&0\\0&0&1\end{pmatrix}}$	${}{\begin{pmatrix}-{\frac {1}{3}}&{\frac {1}{3}}&-{\frac {1}{9}}\\{\frac {2}{3}}&-{\frac {1}{6}}&{\frac {1}{18}}\\0&0&{\frac {1}{3}}\end{pmatrix}}$

Zur gelösten Aufgabe