Translation:I have salt and you have pepper.
if we talking strictly in formal situation, eg. formal letter or business meeting, we must use the formal version.
It's a little bit different when we are in conversation, sometimes we can mix the formal and informal. Also habits have its parts too, eg. use "Aku" means to humble oneself and "Anda" to respect the opponent.
But for education purpose and less confusion, i agree they shouldn't be mixed