Answer
The lines are neither parallel nor perpendicular to each other.
Work Step by Step
RECALL:
(1) The slope-intercept form of a line's equation is:
$y=mx+b$
where $m$ = slope and $b$ = y-intercept
(2) Parallel lines have equal slopes.
(3) Perpendicular lines have slopes whose product is $-1$.
The equations are in slope-intercept form.
The first line has $m=4$ while the second line has $m=-4$.
The slopes are not equal.
The product of the slopes is $-16$.
Thus, the lines are neither parallel nor perpendicular to each other.
