Students may find something interesting in
https://www.mimuw.edu.pl/~krych/ekonomia/ek18/
In the books Linear algebra H-K and Linear algebra J there is a lot of interesting staff from the point of view of the course. Professor Gilbert Strang from MIT allows everybody in the whole wide world to watch him lecturing on linear algebra. The address is https://ocw.mit.edu/courses/mathematics/18-06-linear-algebra-spring-2010/video-lectures/ There are some problems here 60 problems Office hours: if someone thinks that a conversation about mathematics, e.g. Linear Algebra could be helpful she/he should contact me via e-mail to fix a date and time for an online meeting.