Let's write the line in slope-intercept form.
y = mx + b
m = slope
b = y-intercept.
Let's use the two points to calculate our slope.
Slope = (-9 -(-1)) / -3 = -8 / -3 = 8 / 3
Our line so far: y = 8/3x + b
Let's plug one of our points into the equation to find b.
-1 = 8/3(0) + b
-1 = b
Our line is: y = 8/3x - 1