Where $I=\left(\begin{array}{lll}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{array}\right), C=\left(\begin{array}{ccc}0 & -1 & 0 \\ 0 & 0 & -1 \\ 0 & 0 & 0\end{array}\right)$
$C^{2}=\left(\begin{array}{lll}0 & 0 & 1 \\ 0 & 0 & 0 \\ 0 & 0 & 0\end{array}\right)$
$C^{3}=\left(\begin{array}{lll}0 & 0 & 0 \\ 0 & 0 & 0 \\ 0 & 0 & 0\end{array}\right), C^{4}=C^{5}=\ldots .$
$B=7 A^{20}-20 A^{7}+2 I$
$=7(1+c)^{20}-20(1+C)^{7}+2 I$
So
$\mathrm{B} 13=7 \times{ }^{20} \mathrm{C}_{2}-20 \times{ }^{7} \mathrm{C}_{2}=910$
$(I)$ $Trace(R)=0$
$(II)$ જો $Trace(\operatorname{adj}(\operatorname{adj}(R))=0$, તો $R$માં બરાબર એક શૂન્યેતર ધટક હોય
$2 x-y+3 z=5$
$3 x+2 y-z=7$
$4 x+5 y+\alpha z=\beta$
માટે નીચેના માથી ક્યૂ સાચું નથી?