Not sure if this is a homework assignment, but so you know, this isn't the place (and there shouldn't be any place) to have other people do your homework for you.
Secondly, you must tell us what the => symbol means in this context.
I checked Wikipedia, and the pages are written from a retrospective and abstract perspective, rather than explaining things without assuming prior knowledge and experience, so I can't make sense of it.
I'm guessing that valid means that a statement is consistent or correct. For example, 4+5 is valid, 4+/5 is not.
I'll also guess that satisfiable means that the logical statement has at least one solution. For example, 2*3 = ? has a solution of 6. Infinity*zero = ? doesn't necessarily have a solution.