Transcribing informal text into formal language

The question word apa has many unique forms and usages.

Rewrite into formal Indonesian:
Ngapain ke sana? Di sana kan nggak ada apa-apa.

Rewrite into formal Indonesian:
Lagi ngapain? Ikut jalan-jalan ke mall yuk!

Rewrite into formal Indonesian:
Apaan sih pake teriak-teriak segala?