1. Show that the set of points are collinear: a) (-2; -6), (2; -4) and (4; -3) b) (-5; 5), (1; 1) and (4; -1) c) (-5; -6), (-2; 0) and (-1; 2) 6.

2. Calculate the value of x in each case if A, B, C, and D are the points A (-2; 3), B (1; 4), C (-4; 1) and D (x; 4). a) AB || CD b) AB 1 CD c) B, C, and D are collinear.​