Well parallel means that it's going to stay next to a line, but never touch the other line. In order for this to happen, the equation of the line needs to have the same slope as the other line's equation. So, keep the slope the same, but you'll need a new y-intercept.
Rewrite the equation:
y=-1/3x+b
Plug in your points (9,-1):
-1=(-1/3)(9)+b
-1=-3+b
Add 3 to both sides:
2=b
Plug b into your new equation:
y=-1/3x+2 *The answer!! :)
