Out of these equations: which one(s) are the variables not separable? Now I think II and III cannot be separated. I've gotten a little help on this question already but then the activity dwindled down and I didn't really get a complete answer. I appreciate that help though! What I have come up with is that you can obviously separate option I and you cannot separate option III. However I'm not sure if you can separate II or not. I've tried and I can't but maybe that's just because I'm doing something wrong? My answer would be D.II & III cannot be separated but I'm not sure about II. Any help? Thanks!