Algebra/ASSIGNMENTS/matrices

The following are the 2 assignments


 * inverse of a matrix


 * Cayley Hamilton Theorem

Find the sum of the matrices

$$\begin{bmatrix}1&2&3\\2777&3&4\\5&-6&7\end{bmatrix}$$ and $$\begin{bmatrix}12&12&-3\\207&123&-34\\50&61&-7\end{bmatrix}$$