What are the channels on YouTube or books on mathematics?

Question

Books

Please advise books on mathematics, from school knowledge of about 7th grade to higher mathematics, preferably in turn what you need! Or YouTube channels with video courses) Thanks in advance!

Answer 1

Better start then with this: https://ru.khanacademy.org/

Answer 2

I can advise http://mathprofi.ru, everything is explained very intelligibly and with examples that can be caught in practice.
The Valery Volkova channel solves all sorts of interesting tasks from the Unified State Examination.

Answer 3

From the courses:
For practice - khanacademy definitely, but keep in mind that American tasks will pull a maximum of a weak C grade compared to ours - i.e. base-base itself will be given.
There is a Russian-language version of YouTube, but it can be difficult for them to compare the source / translated video.
The theory is excellent in Russian (I haven’t seen anyone better) - Boris Trushin, also on YouTube.
HSE - MIT courses that are in the public domain.
From the books:
School mathematics - very accessible and understandable from Mordkovich.
The tower is what is recommended again in MIT courses from the literature to students.