Mathematics - Matrix Question with Solution | TestHub

$|A|=\left[\begin{array}{lll}2& 0& 0\\ 2& 2& 0\\ 2& 2& 2\end{array}\right]=(2)(2)(2)=8$ Now adj $(\mathrm{adj}A)=|\mathrm{A}{|}^{3-2}\mathrm{A}$ $=8\left[\begin{array}{lll}2& 0& 0\\ 2& 2& 0\\ 2& 2& 2\end{array}\right]=16\left[\begin{array}{ccc}1& 0& 0\\ 1& 1& 0\\ 1& 1& 1\end{array}\right]$