Linux:Unable to install or upgrade firefox in Linux

Installing or upgrading Firefox can be done by using different commands in Linux operating system..
(1) Using yum command you can upgrade your firefox or install.Open terminal and enter su then enter password. Now you are in admin mode so that you can install or upgrade firefox.
For installing anything in linux the user should be in admin mode.
syntax:
$su

$yum update firefox

(2)There is another way of installing firefox in linux that is by using wget command.To use wget command you should have link from where you can download firefox for linux.
Syntax:
$wget link