In the diagram below, OABC is a parallelogram, OA=a and AB=b. N is a point on OA such that ON:NA = 1:2.(a) Find:(i) AC in terms of a and b.(ii) BN in terms of a and b.(b) The lines AC and BN intersect at X, AX=hAC and BX=kBN.(i) By expressing OX in two ways, find the values of h and k.(ii) Express OX in terms of a and b.