Wortels

Uitleg

https://www.youtube.com/watch?time_continue=11&v=MiBlfVcNdSw
https://www.youtube.com/watch?time_continue=6&v=Z1XU0LEPcpA
https://www.youtube.com/watch?time_continue=4&v=qsacdv3TVV0
https://www.youtube.com/watch?time_continue=2&v=PxGUp-PBr3M
https://www.youtube.com/watch?time_continue=5&v=PuNL2_Cm5Tc