You can't. Sorry. You have to go to the Unknown Dungeon in Fire Red/Leaf Green.
There no Mew in firered.
it is mew and mewtwo with a masterball
I don't think you can get Mew in Pokemon FireRed at all. You have to trade a Mew from Emerald. You can go to http://www.serebii.net/pokedex-rs/151.shtml to see what I mean.
Yes, Mewtwo can be caught in Cerulean Cave. As far as Mew is concerned, only hints about it's existence can be found in the Pokémon Mansion at Cinnabar Island. There is no way to catch Mew in Pokemon FireRed of LeafGreen. You have to trade it.
THERE'S NO POKEMON THAT YOU CAN BREED 2 GET MEW...VERONICA
After getting the National Dex, go to Route 229 and there will be MEW floating above the pond, I think he is there because it resembles a similarity to Faraway Island in Pokemon Emerald and it is a rainforest and MEW lives in the rainforest because of the book entrys in the Pokemon Mansion in FR/LG: Deep in the rainforest, we discovered a new pokemon, we cristended the newly found Pokemon as "MEW". Happy hunting :)
In Pokemon Soul silver or silver or gold, the legendaries you can get is Lugia, Suicune, Entai, Raikou, Mew and Mew 2
you go to the statues of mew 2 and press a it will give you an option to flick a switch press yes
sorry no. it's fake. There is a mew and a scientist cloned mew in a movie and created mew 2. the only way there is a mew 3 if they cloned mew 2.
number 151 is mew. If in the regional pokedex its manaphy, which can be found in a book on route 212 in the mansion.
Mew and Mewtwo
no because it is mew!