Given the quadratic equation 3x + y + 6 = 0, when x and y are opposite to each other, what are x and y equal to?

Given the quadratic equation 3x + y + 6 = 0, when x and y are opposite to each other, what are x and y equal to?

3X+Y+6=0,
10. When y is opposite to each other
X+Y=0
3X+Y+6=2X+(X+Y)+6=2X+6=0
We get x = - 3, y = 3