Stage: 5 Challenge Level: 
Consider powers of $1 + x$.
If you can't get started investigate the formula for $n = 2, 3,4 ...$
Inequality/inequalities. Generalising. Mathematical reasoning & proof. Manipulating algebraic expressions/formulae. Visualising. Number theory. Identities. Dynamical systems. Patterned numbers. Binomial Theorem.
Published February 2001.
Copyright © 2007. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project, which also includes the Plus and Motivate sites.
email: nrich@damtp.cam.ac.uk
