Question

помогите пожалуйста!!!!!!!!!!!!!

Answer 1

$A= \left(\begin{array}{ccc}6&7&3\\3&1&0\\2&2&1\end{array}\right) \\\\\\\\ 2A=\left(\begin{array}{ccc}6*2&7*2&3*2\\3*2&1*2&0*2\\2*2&2*2&1*2\end{array}\right)=\left(\begin{array}{ccc}12&14&9\\9&2&0\\4&4&2\end{array}\right) \\\\\\\\ B=\left(\begin{array}{ccc}12&20&-5\\-4&-k&-2\\14&32&-7\end{array}\right) \\\\\\\\ 3B=\left(\begin{array}{ccc}12*3&20*3&-5*3\\-4*3&-k*3&-2*3\\14*3&32*3&-7*3\end{array}\right)=\left(\begin{array}{ccc}36&60&-15\\-12&-3k&-6\\42&96&-21\end{array}\right)$
$\\\\\\\\ 2A-3B=\left(\begin{array}{ccc}12&14&9\\9&2&0\\4&4&2\end{array}\right)-\left(\begin{array}{ccc}36&60&-15\\-12&-3k&-6\\42&96&-21\end{array}\right)= \\\\\\\\ \left(\begin{array}{ccc}12-36&14-60&9+15\\9+12&2+3k&0+6\\4-42&4-96&2+21\end{array}\right)=\left(\begin{array}{ccc}-24&-46&24\\21&2+3k&6\\-38&-92&23\end{array}\right) \\\\\\\\ (2A-3B)^2=\left(\begin{array}{ccc}-24&-46&24\\21&2+3k&6\\-38&-92&23\end{array}\right)^2=$
$\left(\begin{array}{ccc}-24&-46&24\\21&2+3k&6\\-38&-92&23\end{array}\right)*\left(\begin{array}{ccc}-24&-46&24\\21&2+3k&6\\-38&-92&23\end{array}\right)=\\\\\\\\ \left(\begin{array}{ccc}-1302&-1104-46(2+3k)&-300\\-732+21(2+3k)&-1518+(2+3k)^2&642+6(2+3k)\\-1894&-368-92(2+3k)&-935\end{array}\right)$