which are the moves to defeat zapdos ,moltress ,and articuno in the npc fight please give me the best moves

Toxic <- Needed, Blizzard, Fly, Toxic so it's faster/easier to kill before they kill you, Blizzard as an attack, Fly is to dodge attacks, but if you're trying to beat them you probably don't have fly yet :p Those are the main attacks.

thank you ,.........but i dont have toxic how can i get that toxic and what about hyper beam

Toxic- 4500 coins 75,000,000 $ -> [you must login to view links]
Hyper beam isn't worth it, super effective moves are still stronger than Hyper beam.

Phoenix you have forgot about Bolt Strike against Articuno
So Blizzard for Moltres and Zapdos and Bolt Strike for Articuno
If you don't have Toxic, you can try use Sludge, it has a 30% chance of working. I've mananged to beat them once but took many tries using Sludge

thank you guys

dude can any one tell me which are the best pokemon to use I used so many pokemon to defeat zapmolcuno but it don't work