If $2\left|\begin{array}{ll}1 & 3 \\ 0 & x\end{array}\right|+\left|\begin{array}{ll}y & 0 \\ 1 & 2\end{array}\right|=\left|\begin{array}{ll}5 & 6 \\ 1 & 8\end{array}\right|$, then the value of $x$ and $y$ are

If $A$ is a square matrix of order $3 \times 3$, then $|K A|$ is equal to

If $A=\frac{1}{\pi}\left|\begin{array}{ll}\sin ^{-1}(\pi x) & \tan ^{-1}\left(\frac{x}{\pi}\right) \\ \sin ^{-1}\left(\frac{x}{\pi}\right) & \cot ^{-1}(\pi x)\end{array}\right|$

$B=\left|\begin{array}{cc}-\cos ^{-1}(\pi x) & \tan ^{-1}\left(\frac{x}{\pi}\right) \\ \sin ^{-1}\left(\frac{x}{\pi}\right) & -\tan ^{-1}(\pi x)\end{array}\right|$,

then $A-B$ is :

If a matrix $A$ is both symmetric and skew symmetric, then