Question

i need help with matrices

Answer 1

In grey is the code for matrix.
```
\(\large\color{black}{ \displaystyle \left[\begin{matrix}
? & ? & ?~~~|~~~? \\
? & ? & ?~~~|~~~? \\
? & ? & ?~~~|~~~? \end{matrix}\right] }\)
```

you will get the following result:

\(\large\color{black}{ \displaystyle \left[\begin{matrix}
? & ? & ?~~~|~~~? \\
? & ? & ?~~~|~~~? \\
? & ? & ?~~~|~~~? \end{matrix}\right] }\)

Just in case you need the code.

Answer 2

a_rc

r=row,c=column ....