Explanation:
when we have the slope and a point, we usually start with the point-slope form :
y - y1 = a(x - x1)
"a" being the slope, (x1, y1) is the given point.
so, in our case
y - -8 = (-1/3)(x - 6)
y + 8 = (-1/3)x + 6/3 = (-1/3)x + 2
y = (-1/3)x - 6