Formal:
* Oui, je vais bien, merci. (This is the most literal and polite translation.)
Informal:
* Oui, ça va bien, merci. (This is more casual and commonly used among friends and family.)
* Oui, je suis bien, merci. (This is another informal option, emphasizing your well-being.)
Adding "and you?":
* Oui, je vais bien, merci, et vous? (Formal)
* Oui, ça va bien, merci, et toi? (Informal)
The best option will depend on the context of your conversation and your relationship with the person you're talking to.