Answer:
The system has no solution
Step-by-step explanation:
Given the system of equations:
y = -3x - 9 ................................................................(1)
-y = 3x + 9 ...............................................................(2)
To solve by elimination, let us eliminate y by adding equation (1) and (2)
y + (-y) = -3x + 3x - 9 + 9
0 = 0
The variable x has also vanished. We conclude that the system has no solution