Put $x = 0 \Rightarrow \left| {\begin{array}{*{20}{c}}
{ - 4}&0&0\\
0&{ - 4}&0\\
0&0&{ - 4}
\end{array}} \right| = {A^3} \Rightarrow {A^3} = {\left( { - 4} \right)^3}$
$ \Rightarrow A = - 4$
$ \Rightarrow \left| {\begin{array}{*{20}{c}}
{x - 4}&{2x}&{2x}\\
{2x}&{x - 4}&{2x}\\
{2x}&{2x}&{x - 4}
\end{array}} \right| = \left( {Bx - 4} \right){\left( {x - 4} \right)^2}$
Now take $x$ common from both the sides
$\therefore \left| {\begin{array}{*{20}{c}}
{1 - \frac{4}{x}}&{2x}&{2x}\\
{2x}&{1 - \frac{4}{x}}&{1 - \frac{4}{x}}\\
{2x}&{2x}&{2x}
\end{array}} \right| = \left( {B - \frac{4}{x}} \right){\left( {1 + \frac{4}{x}} \right)^2}$
$(I)$ $Trace(R)=0$
$(II)$ જો $Trace(\operatorname{adj}(\operatorname{adj}(R))=0$, તો $R$માં બરાબર એક શૂન્યેતર ધટક હોય