[tkosan]

No currently used step-by-step equation software I am aware of shows all of the steps (inferences) that are needed to solve an equation, and why it took those steps. For example, I just had cymath solve 8x - 2 = -9 + 7x. The solution it provides is missing steps, and there is no explanation of why it took the steps it did. The solver I am writing shows all of the steps needed to solve an equation, and it is capable of explaining why it took these steps (although the "why" part is not shown in the video).

[jupenur]

Wolfram|Alpha does this pretty well, although they moved the step-by-step solver to the paid version quite a while ago and I've only tried the early free version. They also have an extensive knowledge base and other resources that make it very easy to understand even completely new concepts.

And Mathematica of course does everything Wolfram|Alpha can.