Question 115893
Yes, you are right.
For graphing pick two points. 
You already have one point, the intercept (0,8).
Mark that point on your graph paper. 
{{{drawing( 300, 300, -10, 10, -10, 10,grid( 1 ),green(circle( 0, 8, .25 )))}}}
Next pick any other point. 
In your case x=4, makes for easy work.
{{{y=-(3/4)(4)+8}}}
{{{y=-3+8}}}
{{{y=5}}}
Second point is (4,5). 
Plot that on the graph. 
{{{drawing( 300, 300, -10, 10, -10, 10,grid( 1 ),green(circle(4,5,0.25)),green(circle( 0, 8, .25 )))}}}
Then take a straighedge and draw a line between those two points.
{{{drawing( 300, 300, -10, 10, -10, 10,grid( 1 ),green(line(4,5,0,8)),green(circle(4,5,0.25)),green(circle( 0, 8, .25 )))}}}
Extend the line to the limits of your graph and you're done.  
{{{drawing( 300, 300, -10, 10, -10, 10,grid( 1 ),green(line(4,5,0,8)),
green(line(4,5,-4,11)),green(line(4,5,12,-1)),
green(circle(4,5,0.25)),green(circle( 0, 8, .25 )))}}}