Answer
$a.$
A line parallel to the given line has slope $m=-7$.
$b.$
A line perpendicular to the given line has slope $m=\displaystyle \frac{1}{7}$
Work Step by Step
If two nonvertical lines are parallel, then they have the same slope.
If two nonvertical lines are perpendicular, then the product of their slopes is $-1$.
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Reading the slope from $ y=mx+b$
$y=-7x+0:$\quad The given line has slope $m=-7.$
$-7\displaystyle \cdot(\frac{1}{7})=-1$
$a.$
A line parallel to the given line has slope $m=-7$.
$b.$
A line perpendicular to the given line has slope $m=\displaystyle \frac{1}{7}$
