this error is shown while making sudo apt-get update command. I also have error like some dependencies are unmet for some packages. How to sort this?

Question

Err:10 http://ppa.launchpad.net/aims/sagemath/ubuntu focal Release
  404  Not Found [IP: 2001:67c:1560:8008::19 80]
Err:11 http://ppa.launchpad.net/morphis/anbox-support/ubuntu focal Release
  404  Not Found [IP: 2001:67c:1560:8008::19 80]
Err:12 http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu focal Release
  404  Not Found [IP: 2001:67c:1560:8008::19 80]
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/aims/sagemath/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://ppa.launchpad.net/morphis/anbox-support/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Answer 1

You have to disable all three PPAs, which do not support Ubuntu 20.04 LTS (focal):

sudo apt-add-repository -r ppa:aims/sagemath
sudo apt-add-repository -r ppa:morphis/anbox-support
sudo apt-add-repository -r ppa:ubuntu-wine/ppa

and then run update+upgrade procedure again:

sudo apt-get update
sudo apt-get upgrade