By default, there is no sudoer user in Fuduntu 2012.4. Because the sudo feature is debian originally, Fuduntu created their own sudo called beesu.
If you are lazy, you can only alias sudo to beesu, and pretend you are using sudo on a Fedora System:
$ alias sudo="beesu"
To make the alias persistent type this in your terminal: echo ‘sudo=”beesu”‘ >> ~/.bashrc
And now, instead of running beesu yum -y install libreoffice, you run sudo yum -y install libreoffice which replaces in background sudo with beesu and runs beesu yum -y install libreoffice, to install libreoffice.
A better solution is to enable sudo. Actually, sudo is enabled, but only root is a sudoer user, by default.
So, this is how you enable sudo on Fuduntu:
$ su -
Now, create a duplicate line root ALL=(ALL) ALL, and replace root with the user’s name that you want to have sudo access. Like this:
root ALL=(ALL) ALL
your_user ALL=(ALL) ALL
Now, save the changes and exit from vim.