Explanation:
We are given the matrix
[tex]\begin{bmatrix}{6} & {-4} & {8} \\ {} & {} & {} \\ {-6} & {9} & {-9}\end{bmatrix}[/tex]
The first part wants us to give the order of the given matrix
The order of a matrix is given by
[tex]m\times n=Number\text{ of rows}\times number\text{ of columns}[/tex]
We have
[tex]\begin{gathered} rows:\text{ Horizontal} \\ columns:vertical \end{gathered}[/tex]
[tex]\begin{gathered} two\text{ rows} \\ three\text{ columns} \end{gathered}[/tex]
To the order (mxn) is:
[tex]2\times3[/tex]
Part B
We are told to find
[tex]\begin{gathered} a_{31} \\ and \\ a_{13} \end{gathered}[/tex]
To begin with, let
[tex]\begin{gathered} a_{31}\text{ means that we should find the element in the third row and first column} \\ a_{13}\text{ means that we should find the element in the first row and third column} \end{gathered}[/tex]
So
[tex]\begin{gathered} a_{31}:\text{ null, because there is no row 3} \\ Thus,\text{ there is no value} \end{gathered}[/tex]
Then
[tex]\begin{gathered} a_{13}:\text{ 8} \\ Because\text{ the element that coincides with the first row and third column is 8} \end{gathered}[/tex]
