Determine if all $n \times n$ matrices such that $AB = BA$ for a fixed $n \times n$ matrix $B$ form a subspace of $M_{nn}$
95227
Is the set of all $n\times n$ matrices, such that for a fixed matrix B  AB=BA, a subspace of the vector space of all $n\times n$ matrices?
113628
Where M is a matrix calculate a formula for M^n
81868
How to prove $\operatorname{Tr}(AB) = \operatorname{Tr}(BA)$?
128835
Compactness of the set of $n \times n$ orthogonal matrices
58021
Finding matrix $B$ is not zero matrix where $AB= 0$
31326
Number of $(0,1)$ $m\times n$ matrices with no empty rows or columns
25682
If $A$ is an $m\times n$ matrix, $B$ is an $n\times m$ matrix and $n<m$, then $AB$ is not invertible.
25488
Let $A,B$ be $m\times m$ matrices such that $AB$ is invertible. Show $A,B$ invertible.
110502
$AB=BA$ with same eigenvector matrix
84626
Why in these matrices are $AB=BA$ not equal? What is the logic behind them?
53261
Show that Pn is an (n+1)-dimensional subspace
76200
Is the rank of $AB$ always equal to the rank of $BA$?
86841
Find a matrix $B$ such that $B^3 = A$
12955
Classification of $n\times n$ real matrices up to congruence
70021
Verify if symmetric matrices form a subspace
120937
Matrices that commute with all matrices
130498
Linear algebra proof regarding matrices