Which relations are functions?

choose all answers that are correct.

{(2,4), (-1, 7), (3,0), (5,4)}

{(-4,0), (-4,8), (-1, 3), (2,9)}

{(-6, 1), (0, 1), (2, 1), (3, 1)}

{(-3, -3), (-1, 6), (4, 5), (5, 4)}

Given: lines a and b are parallel and line c is a transversal. prove: 2 is supplementary to 8 what is the missing reason in the proof? statement reason 1. a || b, is a transv 1. given 2. ∠6 ≅ ∠2 2. ? 3. m∠6 = m∠2 3. def. of congruent 4. ∠6 is supp. to ∠8 4. def. of linear pair 5. ∠2 is supp. to ∠8 5. congruent supplements theorem corresponding angles theorem alternate interior angles theorem vertical angles theorem alternate exterior angles theorem