Activity $2($Design your own substitution cipher$)$

Hi$,$ please explain your workings in details thanks. Like how you get the $3$x$3$ matrix.

$($a$)$ Use the criteria indicated to create a pair of $33$ matrices $(D$&$D^{-1}),$ where the entries

of the matrix $D$ are all integers.

$(20$ marks $)$

$($i$)d_{2,1}=5$

$($ii$)d_{3,2}=-2$

$($b$)$ Create your own substitution cipher. Then use it and the matrix $D$ you created in $($a$)$ to

encrypt the title of your favourite movie.

$(20$ marks $)$

$($c$)$ Use the matrix $D^{-1}$ and the appropriate substitution cipher to decrypt the message from

$($b$).$

$(20$ marks $)$