We know about the expansion $(a+b)^n\tag 1$,for scalar variables.
What will be the equivalent when we want to find
$(A+B)^n \tag 2 $,
when A and B are square matrices? Can we treat it as same as (1) expression?. Is there any equivalent expression for it?
If $AB=BA$ we have $(A+B)^n=\sum_{k=0}^nC_n^kA^kB^{n-k}$ for the proof see here