What is the rule when adding two (2x2) matrices without like terms?

Question

So given two matrices of 2x2 and adding them together;

Since i am new here and i don't quite know how to format this properly you will just have to try to imagine these are placed in a 2x2 square.

So say from top left to bottom right i have in the first matrices the values 1,3,4,5 and in the second i have the values -2,3,2,a.

Given these two matrices what is the rule when it comes to adding the 5 and the a which are not like terms?

Would the sum of these matrices simply be;

-1,6,6,(5+a)?

Or is it not possible to add them because they do not share like terms?

Answer 1

Yes, you can add two $n\times n$ square matrices $$\begin{pmatrix} 1 & 3 \\ 4 & 5 \end{pmatrix}+\begin{pmatrix} -2 & 3 \\ 2 & a \end{pmatrix}=\begin{pmatrix} -1 & 6 \\ 6 & 5+a \end{pmatrix}$$