We can observe that both the equation represent equation y = mx + c
Rewrite the equations in the form of y = mx + c
3y = 9x + 6
=> y = 3x + 2
2y = 6x + 4
y = 3x + 2
m = slope.
Both the equations have m = 3, since only parallel lines have same slope so the answer is Parallel lines.
Hope This Helps You!