These are all linear equations, which means their graph is a straight line.
So, you need only two points in your chart to draw them accurately.
If you choose them sufficiently far apart, your graph is the most accurate.
For y=2x, lets use -3 and +3:
x y
-3 -6
3 6
Draw dots on the graph paper, then a straight line through them. You can add additional points to the table, they should all fall on the line.
