A = \(\begin{bmatrix}2&6&3\\4&-1&3\\1&3&2\end{bmatrix}\)
|A| = -4 + 18 + 36 + 3 - 18 - 48 = -13
Adj(A) = \(\begin{bmatrix}-11&-3&21\\-5&-1&6\\13&0&-26\end{bmatrix}\)
∴ A-1 = \(\frac{adj(A)}{|A|}\) = \(-\frac1{13}\begin{bmatrix}-11&-3&21\\-5&1&6\\13&0&-26\end{bmatrix}\)