a
(a)The cofactors of $N = \left[ {\begin{array}{*{20}{c}}{ - 4}&{ - 3}&{ - 3}\\1&0&1\\4&4&3\end{array}} \right]$ are
${c_{11}} = - 4,\,{c_{12}} = 1,\,{c_{13}} = 4$;
${c_{21}} = - 3,\,{c_{22}} = 0,\,{c_{23}} = 4$
${c_{31}} = - 3,\,{c_{32}} = 1,\,{c_{33}} = 3$
$\therefore $ $adj\,N = \left[ {\begin{array}{*{20}{c}}{ - 4}&{ - 3}&{ - 3}\\1&0&1\\4&4&3\end{array}} \right] = N$.