No, it isn't. It is an informal expression.
You could use it in everyday conversation and in some neutral contexts. It wouldn't be appropriate in an academic essay or business letter, for example.
5 de mayo de 2015
1
2
0
Informal
It is used when talking to your friends.
5 de mayo de 2015
0
0
¿No has encontrado las respuestas?
¡Escribe tus preguntas y deja que los hablantes nativos te ayuden!