Question 19103
You need to change it into {{{y=mx+b}}}form. 
{{{3y=x}}}
Divide both sides by 3
{{{y=1/3(x)}}}
Your slope is {{{1/3}}} and your Y-intercept is 0
{{{graph(300,200,-5,5,-5,5,(1/3)x)}}}
So looking at your graph, you can see that the points that the line crosses are at (0,0), (3,1), (-3,-1), (6,2),(-6,-2) and so on.
How many points do you need? Just add 3 to the X value and 1 to your Y value.
Hope this helps!