O levels math - Challenging binomial expansion question.

This is a challenging O levels Binomial Theorem question. http://www.numberskill.com/ For more, please subscribe to this channel! http://www.youtube.com/subscription_c... For more videos, please visit http://www.numberskill.com/board-cast... Like us on FaceBook http://www.facebook.com/numberskill Follow us on Google+ https://plus.google.com/+Numberskill-...