A line parallel to the given line has slope 8
A line perpendicular to the given line has slope -1/8
The slope-intercept form is:
y=mx+b
Where m is the slope
In our case:
y=8x
The slope of the line is m=8
If two lines are parallel, they have the same slope.
The slope of a parallel line : m=8
If two lines are perpendicular, their slopes are negative reciprocals of each other:
So:
original slope m= 8 , perpendicular slope : m=-1/8