Answer:
y=-x-1 or, y-8=-1(x+9)
Explanation:
Parallel lines have the same slope. in your current equation you have a slope of -1. We can use this slope and your set of points in the point slope formula.
y-y1=m(x-x1)
(-9, 8)
x1 y1 m=-1
y-8=-1(x+9)
y-8=-1x-9
+8 +8
y=-x-1