The points A(7,−3) and B(−1,5) are fixed in the plane. A variable point P(x,y) divides AB in the ratio λ:1 (with λ=−1) and satisfies the condition x+y=4.
(i) Express x and y in terms of λ.
(ii) Using the given condition, determine the possible value(s) of λ.
(iii) Hence find the corresponding coordinates of P.
(iv) For each value of λ obtained, state whether the division is internal or external and justify your answer.