Answer:
estoy, estas, esta, estamos, estais, están
Explanation:
I think that is Marcos y yo nos servimos pollo
It would be, ¿Cuántos años tienes?
The tu form of tener is tienes
I think it is formal it doesn’t say it formal but it does say the word usted is to show respect so i would say true its formal
Translate this to english i could be able to help u out