okay so my teacher decides to give homework on things unrelated to class lecture, and the book really doesn't help at all. wish the dude could speak english.

anyhoo, i need help with a couple of proofs...

prove the following for complex numbers:

uno: u + v = v + u, and uv = vu for all u, v

dos:u+v=u+vanduv=uxvfor all u, v (the underlines are supposed to be above the numbers...)

tres: u(vw) = (uv)w for all u,v,w