That is flagged as false. It expects AKU MAKAN DI Rumah.
"saya" is more formal :) nothing else
Why not adding "ada" here ?
in this sentence the focus is at what is the person doing in the house, so 'ada' is not needed cause it would be too ineffective since 'di rumah' already explains where does the person eat
thanks you made it easier to understand
'ada' is for showing the position of the person.
Aku ada di rumah -> I'm at the house /I'm at home