Are these lines parallel perpendicular or neither?
y=2x-1/2
y=1/2x-1/2

Neither
If they were parallel then the gradients would be the same but the y intercept would be different. In this case they have different gradients and same y intercept.
If they were parallel then multiplying the 2 gradients would give -1. In this case, 2 x 1/2 gives us 1, not -1.
So they are neither. Hope this is alright and it helps :)

That. you would have multiple