D and E are points on the sides AB and AC respectively of a ΔABC such that DE || BC Find the value of x, when
(i) AD = x cm, DB = (x - 2) cm,
AE = (x + 2) cm and EC = (x - 1) cm.
(ii) AD = 4 cm, DB = (x - 4) cm, AE = 8 cm and EC = (3x - 19) cm.
(iii) AD = (7x - 4) cm, AE = (5x - 2) cm, DB = (3x + 4 ) cm and EC = 3x cm.