Passes through (-9, -3) & has a slope of -6.
Use the slope-intercept form formula.
y = mx+b
Where m=slope, and b=y-intercept.
Our slope is -6, and our y-intercept is -3.
So, simply plug everything in! :)
y = mx+b
y = (-6)x + (-3)
Simplify.
y = -6x - 3
~Hope I helped!~