Hey there! :D
First, find the slope.
m= (y2-y1)/(x2-x1)
m= (-3-0)/(0-(-1)
m=-3-0/0+1
m= -3/1
m=-3
Now, plug that into point slope. I will use the point (-1,0)
y-y1= m(x-x1)
y-0= -3(x-(-1)
y-0= -3(x+1)
y-0= -3x-3
Put it into slope-intercept form.
y=mx+b
Add 0 to the other side.
y=-3x-3 <== equation of the line.
I hope this helps!
~kaikers