To graph a equation you need to find out atleast two point from which equation passes.
For the first point consider x=0,
Substitute 0 for x in the equation to obtain the corresponding y coordinate.
So first point is (0,4).
For second coordinate consider y=0.
Substitute 0 for y in the equation y=2/3x+4 to obtain the value of x.
So second point is (-6,0).
Now draw a line passes through two points (0,4) and (-6,0).
Thus, the graph of equation is obtained.