Write the equation of the line passing through (−1, 0) and (0, −3).

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