Explain when you know you need to rename avmakes numbers do you subtract

In the coordinate plan (-6,9) b (3,9) c (3,3) def is shown in the coordinate plan below

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2

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