Help write a matrix

[Algebra_help]

Here is the question :

I don't know how to answer to this question. Any help would be very appreciate.

We were told to do something like this:

 

[Algebra_help]

View attachment 18721

Here is the question : View attachment 18722

I don't know how to answer to this question. Any help would be very appreciate.

We were told to do something like this: View attachment 18723

I'VE FOUND THE ANSWER THNAKS THOUGH