Essence of linear algebra - YouTube

https://www.youtube.com/watch?v=TBpDMLCC2uY

https://www.youtube.com/watch?v=rowWM-MijXU&list=PLbV6o0GhJgFpNHEr7JljIeVXbvDVfeqS5&index=2&t=5s

https://www.youtube.com/watch?v=i8FukKfMKCI&list=PLbV6o0GhJgFpu7BTGdMXYwf8VVWsZ9phs&index=18

https://www.youtube.com/watch?v=4csuTO7UTMo&list=PLbV6o0GhJgFpu7BTGdMXYwf8VVWsZ9phs&index=10