Question 74917
The x-intercept can be written as point (12,0) and the y-intercept can be written as (0,4).  

If you use the slope-intercept form for a line ({{{y=mx+b}}}), then you must find {{{m}}}, which is the slope, and b, which is the y-intercept.

To find {{{m}}}, use the formula {{{(y[1]-y[2])/(x[1]-x[2])}}}. 
Plug the points in:
{{{(0-4)/(12-0)}}}={{{-1/3}}}

Now that you have the value of {{{m}}} and you have the value of {{{b}}} given to you in the question (4), you can plug the numbers into the slope-intercept formula for the equation of your line.

{{{y=-(1/3)x+4}}}

That line graphed would look like:
{{{graph(500,500,-15,15,-15,15,-(1/3)x+4)}}}

Hope this helps!