Question 18991
You want to convert each equation into {{{y=mx+b}}} form.
For your first equation, I don't know where you equal sign is. 
I'll assume it is {{{x=y-3}}}
{{{-y=-x-3}}}
{{{y=x+3}}}
{{{graph(300,200,-5,5,-5,5,x+3)}}}
Second equation
{{{x=3y}}}
{{{-3y=-x}}}
{{{y=(1/3)x}}}
{{{graph(300,200,-5,5,-5,5,(1/3)x)}}}
Hope this helps!