Khan/khan-exercises — pull request #71140 by sabinem (2013-09-05 12:46:54+00:00)
Title: I made a new exercise for the video "Binomial Theorem (part1) of your list of videos needing execises.

This exercise is about the geometrical interpretation of the binomial theorem. The student uses a geometric interpretation of this theorem to quickly compute the square of linear polynomial such as (3x + 9), were the square is interpreted as the area of a square and the binomial theorem is interpreted as dividing this square into parts corresponding to the powers of x.

I call this problem "forward", since computing the square this is the easier task, that none the less prepares students for the harder task of solving a quadratic equation by completing the square and thereby using the binomial theorem backward.