Let us plot the points (-3, 6), (-2, 4), (0, 0), (1, -2), (2,-4), (3,-6) in the coordinate plane on a graph paper as shown in Fig. 2.7. Join the points (-3, 6) and (3, -6) using a ruler. Doing so, observe that all five points lie on a straight line. Can you guess the equation of this line by looking at the relationship between the x and y coordinates of each point?