step 1
Find out the slope of the given line
we have
y=-3x-2
the slope is m=-3
Remember that
If lines are perpendicular, then their slopes are negative reciprocal
that means
the slope of the perpendicular line to the given line is
m=1/3
step 2
Find out the equation of the perpendicular line
y=mx+b
we have
m=1/3
point (-7,-1/3)
substitute and solve for b
-1/3=(1/3)(-7)+b
-1/3=-7/3+b
b=-1/3+7/3
b=2
therefore
the equation of the line is
y=(1/3)x+2
