what is the answer to this equation

the equation of the following line (0,0) and (-3,1)
First we find slope of the line using the given points (0,0) and (-3,1)
[tex]slope = \frac{y_2-y_1}{x_2-x_1}[/tex]
(0,0) is (x1,y1) and (-3,1) is (x2,y2)=
[tex]slope = \frac{1-0}{-3-0}[/tex]= [tex]\frac{-1}{3}[/tex]
Now we use equation y=mx+b
where m is the slope and b is the y intercept
[tex]y=\frac{-1}{3}x +b[/tex]
Plug in (0,0) and solve for b
[tex]0=\frac{-1}{3}(0)+b[/tex]
b=0
So equation of the line is
[tex]y=\frac{-1}{3}x [/tex]