Discrete Mathematics - (A∪B)-(A∩B)=(A-B)∪(B-A) - prove by cases?? Hi, I'm new to these forums so please redirect me if I've posted this in the wrong place. I'm trying to graduate and this is my last class, but as I'm not a math major, I'm really struggling with this particular problem. I've been able to manage most other simple proofs pretty well, but this one has me stumped: (A∪B)-(A∩B)=(A-B)∪(B-A) The instructor hinted that this problem could/should be done with Proof by Cases. Any chance someone could walk me through this?? Like I said, I've managed to handle other similar problems but the elements of this one have me thrown.... any help would be appreciated. I tend to learn well by example, but there's nothing in my notes/textbook that show a similarly structured problem... Thanks!