Calculate the slopes of a line to determine if the pairs of lines are parallel, perpendicular, or neither. 1. Find the slope of the line passing through the points (2,5) and (1,2) and the slope of the line passing through the points (-1,7) and (-2,4). Are the slopes equal, negative reciprocals, or neither? 2. Find the slope of the line passing through the points (-1,2) and (4,2) and the slope of the line passing through the points (5,9) and (-1,9). Are the slopes equal, negative reciprocals, or neither?