I have two living rooms set up. How do I combine them.

Only by grouping them.

or if they are like speakers you can make a left/right stereo pairing.

I can group the two living rooms together but would rather just have one living room. Can I delete both and add them?

Depends on what kind and number of speakers you have. For instance, you can't have two PLAYBARS in the same "room", so as jgatie suggested, you'd have to group them.

Which speakers do you have in each "living room"?

Yes if you have say two play:1s. Go into settings. Room settings. Choose one of the play:1s and then choose option to stereo pair and follow instructions.

No do not reset any speaker - that would do you no good.

I had a 301 in a spare room. I've tried to add a 501 to it but even though the app accepted the same name, it did not combine the speakers. I now have two rooms with the same name. Is there anyway to combine so that I don't have to group the two rooms all the time? thx! MF

I am not sure what a 301 and a 501 are, but if they are different Sonos speskers then you have to rename one of your rooms, then group them if you want them to play in sync. The room names are just labels, so giving two speakers the same name creates only confusion.