If we plug x=0, we'll find the y intercept:
[tex]y = -\dfrac{1}{3}\cdot 0+4 = 4[/tex]
If we plug y=0, we'll find the x intercept:
[tex]0 = -\dfrac{1}{3}x+4 \iff \dfrac{1}{3}x=4 \iff x = 12[/tex]
So, the line passes through the points (0,4) and (12,0)