In the formal translation, qual é o seu nome? is used, which is a polite and respectful way to ask someone's name. The use of seu (your) instead of teu (your) also adds formality to the. Sinônimo de whats what's=what is whats doesn't exist|whats and what's mean the same thing but whats is the improper way to spell what's.

Whats é what's escrito.