Describe the error in determining whether the lines are parallel, perpendicular, or neither.

Step-by-step explanation:
The slopes of perpindicular lines must be negative reciprocals of each other -- while -4 and 4 are negative to each other, the negative recipricocal for -4 is 1/4 and -1/4 for 4.
The slopes of parallel lines must be the same, so these are not parallel.