Vectors, ABC isoceles Triangle.

[TehNewbie]

Consider the triangle ABC. Let P divide the segment AB in the ratio s : t, and Q divide the segment BC in the ratio t : s.


(a) Draw a sketch of the situation.
(b) Express the vector PQ in terms of t, s, and AC.
(c) Hence explain why PQ and AC are parallel


I understand Part A and realise that the length of AB = PQ, and can also see how PQ is parallel to that of AC. Just unsure on how to express PQ.

 

[pka]

Consider the triangle ABC. Let P divide the segment AB in the ratio s : t, and Q divide the segment BC in the ratio t : s.
(a) Draw a sketch of the situation.
(b) Express the vector PQ in terms of t, s, and AC.
(c) Hence explain why PQ and AC are parallel

You have received almost complete solution here.
Are you too lazy to even try to use it?