x+2y=6
2y=6-x
y=(6-x)/2
y=3-0.5x
Again,
Parallel means same slope,
Perpendicular means negative recipricol of slope, in this case 2
Neither is neither.
Thus first is parallel
Second is y=-4+2x perpendicular
Third is 2y=2+x, y=1+0.5x so neither
fourth is 2y=-2-x, y=-1-0.5x so neither.