How to delete some of these sources, as shown in picture, via terminal? Help would be greatly appreciated.
1 Answer
These are usually stored in /etc/apt/sources.list or /etc/apt/sources.list.d
I'd recommend backing up sources.list and sources.list.d, then simply editing out the lines you don't want, or deleting the files with the entries you don't need in sources.list.d.
Run apt update and the sources you removed will be gone.