Let A, B, and C be three collinear points s.t. A*B*C. Prove each of the follow set equalities. I'm really having trouble applying theorems like the ruler placement postulate or betweenness theorem to help prove these.

24. Let A, B, and C be three collinear points such that A * B * C. Prove each of the following set equalities. (a) B U B " (b) BA n BC {B} (c) ABU BC AC (d) AB n BC {B} (e) AB - AC