Question

1. what should always be the first statement in a formal proof?

counterexample
given
conclusion
theorem

Explanation:

In a formal proof, we start with the information that is provided to us. A counterexample is used to disprove a statement, not to start a proof. The conclusion is the end - result of the proof. A theorem is a general statement that we may prove, but we first need to state what is given.

Answer:

Given