отказ установить sagemath на ubuntu 18.04 LTS

Недавно, я имею, устанавливают Ubuntu 64amd, делающую duak начальная загрузка с Windows 7 32bit. Все в порядке, но я не могу установить sagemath в нем. это говорит "не могущий определить местоположение пакета sagemath-upstream-binary", даже когда код является правильным. я могу знать почему?

Вот полный код, который я использовал:

sudo apt-add-repository -y ppa:aims/sagemath
sudo apt-get update
sudo apt-get install sagemath-upstream-binary  

Ниже терминальные коды:

kutubuddin@kutubuddin-h81m-s:~$ sudo apt-add-repository -y ppa:aims/sagemath
[sudo] password for kutubuddin: 
Ign:1 http://ppa.launchpad.net/aims/sagemath/ubuntu bionic InRelease           
Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [69.9 kB]    
Err:3 http://ppa.launchpad.net/aims/sagemath/ubuntu bionic Release             
  404  Not Found [IP: 91.189.xx.xx xx]
Hit:4 http://in.archive.ubuntu.com/ubuntu bionic InRelease                     
Hit:5 http://in.archive.ubuntu.com/ubuntu bionic-updates InRelease             
Hit:6 http://in.archive.ubuntu.com/ubuntu bionic-backports InRelease           
Reading package lists... Done                                  
E: The repository 'http://ppa.launchpad.net/aims/sagemath/ubuntu bionic 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.
kutubuddin@kutubuddin-h81m-s:~$ sudo apt-get update
Ign:1 http://ppa.launchpad.net/aims/sagemath/ubuntu bionic InRelease
Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [69.9 kB]
Hit:3 http://in.archive.ubuntu.com/ubuntu bionic InRelease                     
Err:4 http://ppa.launchpad.net/aims/sagemath/ubuntu bionic Release             
  404  Not Found [IP: 91.189.xx.xx.xx]
Get:5 http://in.archive.ubuntu.com/ubuntu bionic-updates InRelease [65.4 kB]   
Hit:6 http://in.archive.ubuntu.com/ubuntu bionic-backports InRelease           
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/aims/sagemath/ubuntu bionic 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.
kutubuddin@kutubuddin-h81m-s:~$ sudo apt-get install sagemath-upstream-binary
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package sagemath-upstream-binary