Perform these matrix operations


Adjugate $\displaystyle \left[\vphantom{
\begin{array}{ll}
97 & 50 \\
56 & 49
\end{array}
}\right.$$\displaystyle \begin{array}{ll}
97 & 50 \\
56 & 49
\end{array}$$\displaystyle \left.\vphantom{
\begin{array}{ll}
97 & 50 \\
56 & 49
\end{array}
}\right]$


.                Concatenate $\displaystyle \left[\vphantom{
\begin{array}{ll}
a & 5 \\
6 & b
\end{array}
}\right.$$\displaystyle \begin{array}{ll}
a & 5 \\
6 & b
\end{array}$$\displaystyle \left.\vphantom{
\begin{array}{ll}
a & 5 \\
6 & b
\end{array}
}\right]$$\displaystyle \left[\vphantom{
\begin{array}{ll}
9 & c \\
d & 4
\end{array}
}\right.$$\displaystyle \begin{array}{ll}
9 & c \\
d & 4
\end{array}$$\displaystyle \left.\vphantom{
\begin{array}{ll}
9 & c \\
d & 4
\end{array}
}\right]$


.

Find the determinant of $\displaystyle \left[\vphantom{
\begin{array}{ll}
a & b \\
c & d
\end{array}
}\right.$$\displaystyle \begin{array}{ll}
a & b \\
c & d
\end{array}$$\displaystyle \left.\vphantom{
\begin{array}{ll}
a & b \\
c & d
\end{array}
}\right]$.