Find the uncoded $13$ row matrices for the message "TWO IF BY LAND" by assigning a

number to each letter in the alphabet $($with $0$ assigned to a blank space, $0={?}_{-},1=A,2=$

$B$ and so on$.).$

Then encode the message using the encoding matrix $\left[\begin{array}{ccc}0& -1& 1\\ 1& -3& 3\\ -3& -1& 0\end{array}\right].$ Show all your work.

Write a cryptogram for the message "MERRY CHRISTMAS" using the matrix

$\left[\begin{array}{ccc}0& 5& 1\\ -2& 1& 2\\ 2& -5& 0\end{array}\right]$ by assigning a number to each letter in the alphabet $($with $0$ assigned to a blank

space, $0=$dots,$1=A,2=B$ and so on$.).$ Show all your work.

Show that $A^3-9A+10I=0$ when:

$A=\left[\begin{array}{ccc}1& -2& 2\\ 0& 2& 0\\ 1& -1& -3\end{array}\right]$