$\mathrm{A}_{2} \mathrm{B}_{2} \mathrm{C}_{2}=100 \mathrm{A}_{2}+10 \mathrm{B}_{2}+\mathrm{C}_{2}=\mathrm{q} \mathrm{k}$
$\mathrm{A}_{3} \mathrm{B}_{3} \mathrm{C}_{3}=100 \mathrm{A}_{3}+10 \mathrm{B}_{3}+\mathrm{C}_{3}=\mathrm{rk}\left(\text { where } \mathrm{p}_{1} \mathrm{q}_{1} \mathrm{r} \in \mathrm{I}\right)$
so $\Delta=\mathrm{C}_{3} \rightarrow \mathrm{C}_{3}+100 \mathrm{C}_{1}+10 \mathrm{C}_{2}$
$\Delta=\left|\begin{array}{lll}{\mathrm{A}_{1}} & {\mathrm{B}_{1}} & {\mathrm{pk}} \\ {\mathrm{A}_{2}} & {\mathrm{B}_{2}} & {\mathrm{qk}} \\ {\mathrm{A}_{3}} & {\mathrm{B}_{3}} & {\mathrm{rk}}\end{array}\right|=\mathrm{k} \cdot$ Integes (divisible by $k$ )
$\left| {\begin{array}{*{20}{c}}
{ - 1 + \cos B}&{\cos C + \cos B}&{\cos B} \\
{\cos C + \cos A}&{ - 1 + \cos A}&{\cos A} \\
{ - 1 + \cos B}&{ - 1 + \cos A}&{ - 1}
\end{array}} \right|$ ની કિમંત મેળવો.
$x+y+a z=b$
$2 x+5 y+2 z=6$
$x+2 y+3 z=3$
ને અસંખ્ય ઉકેલો હોય, તો $2 a+3 b=.......$