To this result add the 1st eqn: 6x -3y = 18 ------------------- Adding these eqns together: 0 = -6y = 0. This can be solved for y: y = 0. Then -2x - 0 = -6, and x = 3.
This system has the solution x=3, y=0: (3,0). Check it!
Thus, we dub this system of linear equations "consistent."