line 1
3y = 4x + 5
y = 4/3x + 5/3
line 2
8x + 6y = -4
6y = -8x -4
y = -8/6x -4/6
y = -4/3x - 2/3
line 3
y = 3/4x + 6
since line 1 and 2 have different slopes, they are neither
since line 1 and 3 have different slopes, they are neither
since line 2 and 3 have the opposite slopes, they are perpendicular