With Mozilla Firefox 31 Google was removed as a search engine and the Yahoo search provider was used by default.
By default in Firefox for Linux Mint and Ubuntu you have several search engines but Google is missing. If you want to added you can do:
- Open Firefox
- Search - from the left pane
- Search Bar - optional - in order to have separate search bar
- Find more search engines - at the bottom
- Other search engines - at the bottom
- Select search engine and click on it
- Youtube - as an example
- Click here to add Youtube to your search engines.
The link for Linux mint and more search engines: