To find the slope of a line given two points, use: (y2 - y1) / (x2 - x1)
A. (7-3) / (-1-5) = (4/-6) or -2/3
B. The slope of a line parallel to another line will be the same, so -2/3
C. The slope of a line perpendicular to another line will be the reciprocal and the sign will also change. Because the slope was -2/3, the slope of the perpendicular changes to 3/2 (positive)