I tried to install skype using this tutorial https://help.ubuntu.com/community/Skype But I got troubles at the first step
sudo dpkg --add-architecture i386
When I wrote this, I got this message
$ sudo dpkg --add-architecture i386
dpkg: error: unknown option --add-architecture
Type dpkg --help for help about installing and deinstalling packages
[*]; Use `dselect' or `aptitude' for user-friendly package management;
Type dpkg -Dhelp for a list of dpkg debug flag values;
Type dpkg--force-help for a list of forcing options;
Type dpkg-deb --help for help about manipulating *.deb files;
Options marked [*] produce a lot of output - pipe it through `less' or`more' !
What should I do ? I will be very thankful if you will explain all this step by step, because I never had Ubuntu before.