y = 3x + 3 clearly intercepts the y-axis at y=3 (just set x=0 to see this). This is the point (0,3). Pick any other value for x and then you will have a 2nd point: say x=2, y = 3(2) + 3 = 9. So (2,9) is another point on the line. Plot the two points then draw a straight line through them, that is y = 3x+3.
