Недостающие пакеты Steam

В Ubuntu 14.04, когда я пытаюсь установить steam через файл.deb, он показывает:

Steam needs to install these additional packages: libgl1-mesa-dri:i386, libgl1-mesa-glx:i386, libc6:i386

Затем он запрашивает мой пароль. Я ввожу свой пароль, терминал загружается, а затем говорит следующее:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libgl1-mesa-glx:i386 : Depends: libglapi-mesa:i386 (= 10.1.3-0ubuntu0.5)
 unity-control-center : Depends: libcheese-gtk23 (>= 3.4.0) but it is not going to be installed
                        Depends: libcheese7 (>= 3.0.1) but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages."

Пакеты, похоже, не хотят устанавливать. Любой вклад?

Я новичок в Ubuntu. Пожалуйста, будьте конкретны с командами.