1. The problem statement, all variables and given/known data Suppose that A is an m x n matrix and there exists n x m matrices C and D such that CA=In and AD=Im. Prove that C=D 2. Relevant equations 3. The attempt at a solution Im not sure if I'm on the right path here. However my initial thought is that since the matrices are not square there isn't anything to prove by using inverses. So my guess would be i need to use the definition of matrix multiplication on CA=In and AD=Im and try and equate C and D in some way.