To see if the ordered pair is indeed a solution, you must plug in each of the x and y values in the ordered pair into both the equations. If each equation is true, than the ordered pair is a solution.
-12 = 6(-4) + 12
-12 = -12
The first equation is true!
-12 = 2(-4) - 4
-12 = -12
Both equations are true! (-4, -12) is a solution to the system.
Hope this helps! :)
