Quantum/math question :) 1. The problem statement, all variables and given/known data I need to expand the commutator of the 3 operators A,B,C: [A,BC] in terms of [A,B], [A,C], [B,C]. 2. Relevant equations [A,B] is defined to be AB - BA also, [A,BC] = B[A,C] +[A,B]C. There are some other identities but none that I see relevant. 3. The attempt at a solution Tried lots of opening and additing/substructing of elements using the above formulas but I could never get rid of "operators". Is the a way to write "B" and "C" in terms of the above? I'm working on this for over an hour! :( Thank you very much! Tomer.