Would these lines be parallel,perpindicular or neither 9x+3y=6 and 3x+9y=6

9x + 3y = 6
3y = - 9x + 6
y = - 9/3x + 6/3
y = - 3x + 2
Slope is -3

3x + 9y = 6
9y = - 3x + 6
y = -3/9x + 6/9
y = - 1/3x + 2/3
Slope is - 1/3
neither parallel nor perpendicular

if the lines were parallel they would have the same slope
If they were perpendicular the slopes would be negative reciprocal