Multiple commands are listed

wiki/src/install/expert/usb.mdwn

@@ -135,7 +135,7 @@ Installer</span>, a program designed specifically for installing Tails.
 
 1. If you are running:
 
-   a. Debian, execute the following command to add the
+   a. Debian, execute the following commands to add the
    backports repository to your system:
 
          BACKPORTS='deb http://http.debian.net/debian/ stretch-backports main'