How do I add my Play 5 to an existing “Room” but still be able to use seperately if I want?

Hey Folks, 

Sonos Newbie here. I have my living room set up with an Arc, two 1s and a sub. I later bought a Play 5 and set it up to play separately on my patio. 
 

So I currently have:

Living Room & 

Deck Speaker displaying separately in the App. 
 

I’d like to add the Play 5 to my Living Room to be able to play the same music simultaneously in the Living Room and on the patio but still be able to use the 5 by itself when I want. 
 

Any direction would be appreciated. Thank you all in advance for your help 😊👊🏽