How do we usually form a question in the Present Simple? By using do (for I / you / we / they) or does (for he / she / it) and the base form of the main verb.
Do you live in Malta?
Does your daughter visit you often?
It is not necessary to use do or does when the verb is to be.
Are you from Malta?
Is that your car?
Let’s look at the question
Are you agree?, which is incorrect. The main verb is to agree. Therefore, following the rule we saw earlier on, the correct question is Do you agree?
Similarly, the answer
I am agree is wrong. Simply say I agree.
There is a way of using are you to form a question with the same meaning. In this case, we need the noun of agree, which is agreement – Are you in agreement?
This means that the answer I’m in agreement is also valid.
In my opinion, these are more formal and should be avoided when having a discussion with friends or family.