Square roots

If you haven't already, Khan Academy has some content on simplifying square roots with variables that should help you out. There are also exercises that give you the explanation step by step if you need help.

If you give it a shot and need some more help, let me know (I can wirte out some example solutions to guide you further). It can be a little tough to fully understand the work process given in the explanations when first beginning to learn concepts, but my suggestion would be to keep at it and reach out to your teacher(s) and us in the community if you need assistance; we're always here! ;D