The exercise states that Line 1 passes through (3,-5) and (2,-1). Furthermore, it also states that Line 2 passes through the points (0,3) and (1,7). The slopes of both lines are correctly calculated using the Slope Formula. Line 1:Line 2: (3,-5) and (2,-1)⇒slope: -4 (0,3)- and (1,7)-⇒slope: -4 The lines are not parallel because the slopes are not the same. To determine whether or not they are perpendicular, we multiply the slopes. -4(4)=-16 We see that the product of the slopes is not -1. Therefore, the lines are not perpendicular. The error was thinking that, because the slopes are opposite, the lines were perpendicular. The conclusion should be that lines 1 and 2 are neither parallel nor perpendicular.