It is a negation in mathematics? Okay, sure you're not unique, but now has a handy utility that you can be of great help: Bagatrix Solved!.
These applications will help you with basic problems and theories of matter, explaining step-by-step how issues are resolved in each of the topics they cover, with the help of a nice interface that mimics the look of a notebook.
The user has available to dozens of examples with the help of a little wizard in wizard mode. It also allows the creation and testing for knowledge that are proven.