Copyright © University of Cambridge. All rights reserved.

## 'Minus One Two Three' printed from http://nrich.maths.org/

Look at the two brackets for the factors that make the product. You
are evaluating it for $x$ values of -1, -2, and -3 . Think what you
could change systematically about those factors and see how it
affects the size of the product for each of the three $x$
values.