The mid point of the line joining the points (4,5) and (a,3) is (12,4) so that a=
Show that the line joining the points (2,-3) and (-5, 1) is parallel to the line joining the points (7,-1) and (0, 3) and perpendicular to the line joining (4, 5) and (0,-2).
Find the slope of a line, which passes through the origin, and the mid-point of the line segment joining the points A (0, -4) and B (8, 0).