If $AB = I$ then $BA = I$: is my proof right?
3301
If $AB = I$ then $BA = I$
140290
Solving $AB - BA = C$
106305
Prove/disprove: if $\det(A+X) = \det(B + X)$ for all $X$, then $A=B$
6096
If $A+B=AB$ then $AB=BA$
123555
Proving that if $ab=e$ then $ba=e$
115460
Proving $a\mid b^2,\,b^2\mid a^3,\,a^3\mid b^4,\ldots\implies a=b$ - why is my approach incorrect
120292
How to formally prove: if $d\mid da+b$, then $d\mid b$?
7622
$AB-BA=I$ having no solutions
17032
If $ab=ba$, Prove $a^2$ commutes with $b^2$
31783
Is this proof of $ab = 0$ correct?
29692
Proof verification: elementary Number Theory Proof of $am+bn = 1$
13346
If $A=AB-BA$, is $A$ nilpotent?
7015
Prove that if $(ab)^i = a^ib^i \forall a,b\in G$ for three consecutive integers $i$ then G is abelian
64077
$I_m - AB$ is invertible if and only if $I_n - BA$ is invertible.
158695
Prove that if $AB$ is invertible then $B$ is invertible.
63535
Prove that if $A – C = B – C$ and $A\cap C = B\cap C$ then $A = B$
46286
Prove if $a\mid b$ and $b\mid a$, then $|a|=|b|$ , $a, b$ are integers.