You draw a line with the gradient 3/4 - that is if you go right 4 steps and 3 steps up, if you have a squared notebook. Then you subtract 3 on the whole line.ORGo to the origin of the coordinate system. Go down 3 units. Mark the point. (0/-3)Go right 4 steps and 3 steps up and mark this point, too. (3/0)Draw a line between these points.OR In general: This is a straight line equation. The 3/4 ist the gradient of the line and the -3 the Y axis intercept.