Sample Response: Line BC is parallel to line AD. The system of equations has the sum 0 = 14. Since this is a false equation, the system has no solution, which means the lines will never intersect.
For any rectangle or square located on the axes, match the pairs and find what's missing. 3 -- 3, 4 -- 4. unmatched are 4 and 1. 4 is x because it's missing from x and same for 1 and y.