You can read the points from the line from the graph. 

For x = 0 we have

y = (-8/3)*0

y = 0

One point is (0, 0)

For x = 3

y = (-8/3)*x

y = -8

Second point is (3, -8).

We need to two points to draw a line thus you draw a line trough (0,0) and (3, -8):