Solve for y:
[tex]\dfrac{2}{3}x+\dfrac{1}{3}y=2\ \ \ \ |\cdot3\\\\2x+y=6\ \ \ \ |-2x\\\\y=-2x+6[/tex]
It's the slope intercept form of a straight line.
We need only two points to draw a straight line.
[tex]for\ x=0\to y=-2(0)+6=0+6=6\to(0;\ 6)\\for\ x=3\to y=-2(3)+6=-6+6=0\to(3;\ 0)[/tex]
Look at the picture.