Given: (1) y = -8
            (2) y = -2x - 12
Using substitution method, we will solve this by following these steps.
Step 1: Substitute (1) to (2)
        (1) y = -8
       (2) y = -2x - 12
            -8 = -2x - 12
Step 2: Add 12 to both sides of the equation
          -8 + 12 = -2x - 12 + 12
                  4 = -2x
Ste 3: Divide both sides with -2
                4 / 2 = -2x / -2
                    2 = x
                     x = 2
Therefore, the solution of the system is x = 2 and y = -8