Is khan academy a good place to learn math?
My opinion is yes, because it covers a lot of thing, that are explained well with visual examples and also offers good exercises, if you try to do mastery of the subject you'll do alot of them and repeat alot, that helps cement the knowledge in your head, only con is that it lacks a bit of formal explanations and definitions, but once you learn it the khan academy way when you go look the more formal stuff it's easy to understand it and learn it too compared to doing that first.