Bonjour voici ce que les commandes demandées m'ont données:
/eric@PC-Linux:~$ find /etc/apt -type f -name '*.list' -exec bash -c 'echo -e "\n$1"; nl -ba "$1"' _ '{}' \;
/etc/apt/sources.list
1 #
2
3 # deb cdrom:[Debian GNU/Linux 10.7.0 _Buster_ - Official amd64 NETINST 20201205-11:16]/ buster main
4
5 #deb cdrom:[Debian GNU/Linux 10.7.0 _Buster_ - Official amd64 NETINST 20201205-11:16]/ buster main
6
7 deb
http://ftp.fr.debian.org/debian/ buster main
8 deb-src
http://ftp.fr.debian.org/debian/ buster main
9
10 deb
http://security.debian.org/debian-security buster/updates main
11 deb-src
http://security.debian.org/debian-security buster/updates main
12
13 # buster-updates, previously known as 'volatile'
14 deb
http://ftp.fr.debian.org/debian/ buster-updates main
15 deb-src
http://ftp.fr.debian.org/debian/ buster-updates main
16
17 # This system was installed using small removable media
18 # (e.g. netinst, live or single CD). The matching "deb cdrom"
19 # entries were disabled at the end of the installation process.
20 # For information about how to configure apt package sources,
21 # see the sources.list(5) manual.
eric@PC-Linux:~$ apt show firmware-amd-graphics
Package: firmware-amd-graphics
State: pas un véritable paquet (virtuel)
N: Impossible de choisir une version candidate du paquet « firmware-amd-graphics » qui n'en n'a pas
N: Impossible de choisir les versions du paquet « firmware-amd-graphics » qui n'est qu'un paquet virtuel
N: Aucun paquet n'a été trouvé
Pour la deuxième:
eric@PC-Linux:~$ cat /etc/apt/sources.list
#
# deb cdrom:[Debian GNU/Linux 10.7.0 _Buster_ - Official amd64 NETINST 20201205-11:16]/ buster main
#deb cdrom:[Debian GNU/Linux 10.7.0 _Buster_ - Official amd64 NETINST 20201205-11:16]/ buster main
deb
http://ftp.fr.debian.org/debian/ buster main
deb-src
http://ftp.fr.debian.org/debian/ buster main
deb
http://security.debian.org/debian-security buster/updates main
deb-src
http://security.debian.org/debian-security buster/updates main
# buster-updates, previously known as 'volatile'
deb
http://ftp.fr.debian.org/debian/ buster-updates main
deb-src
http://ftp.fr.debian.org/debian/ buster-updates main
# This system was installed using small removable media
# (e.g. netinst, live or single CD). The matching "deb cdrom"
# entries were disabled at the end of the installation process.
# For information about how to configure apt package sources,
# see the sources.list(5) manual.
merci par avance