Answer: They are neither
Step-by-step explanation:
Parallel lines have the same slope, but different y-intercepts. If they have the same slope and y-intercepts they are the same line.
Perpendicular lines have opposite reciprocal slopes.
Example:
[tex]y=\frac{1}{2}x+3[/tex]
The line perpendicular to this is: [tex]y=-\frac{1}{2}x+4[/tex] not [tex]y=\frac{1}{2}x+4[/tex]
(y-intercepts don't matter for perpendicular lines)