Answer two questions about Systems AAA and BBB: System AAA \text{\quad}start text, end text System BBB \begin{cases}x-7y=-34x+y=7\end{case s} ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ x−7y=−3 4x+y=7 \begin{cases}4x+y=7x-7y=-3\end{case s} ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ 4x+y=7 x−7y=−3 1) How can we get System BBB from System AAA?

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