Does this work ? If ..... than ....

[Lazar]

A , B are 2 matrix A n*n , B n*n ; n e N ,

If AB^-1 = (B^-1) * A
does A*B= B* A ?

I cant find this formula nowhere , so I would really appreaciate it if some1 could help me ?

 

[JohnZ]

yes
A*B^-1 = B^-1*A
A*B^-1*B = B^-1*A*B => A = B^-1*A*B
B*A = B*B^-1*A*B = A*B

 

[Lazar]

Thanks Johnz .