#### Answer

First check if the matrices have the same order.
If not, the difference is not defined.
To obtain the element in row i, column j,
subtract the corresponding elements.

#### Work Step by Step

A matrix is a set of numbers, arranged into rows and columns, placed in brackets.
The numbers inside the brackets are called elements of the matrix.
A matrix of order $m\times n$ has $m$ rows and $n$ columns.
To subtract two matrices, they must have the same order. Otherwise, the sum is not defined.
If we annotate $A=[a_{ij}]$ and $B=[b_{ij}]$, then
$A-B=\left[a_{ij}-b_{ij}\right]$
To obtain the element in row i, column j,
subtract the corresponding elements.