Firefox doesn't run on Chromebooks.

I have read that you can install a standard version of Linux on a Chromebook. (For example: http://www.pcworld.com/article/298483.../installing-linux-on-a-chromebook-what-you-need-to-know.html) Then you could run Firefox for Linux. But... I don't know if this is a great idea.

The desktop Firefox is only for Windows, Mac OSX, and Linux www.mozilla.org/firefox/all/ and Firefox for Android https://www.mozilla.org/firefox/android/all/

Chromebooks run Chrome OS. Essentially the Chrome browser is the operating system.

You cannot install any third-party software, including other browsers like Firefox.

The only way to have Firefox on this laptop is by installing or dual booting with certain Linux distro. However you may not be able to on some Chromebooks due to hardware.