Khan/khan-exercises — pull request #12073 by dsissitka (2012-01-25 10:07:00+00:00)
Title: Created "Proportions 1".

This is re [Proportions 1](https://trello.com/card/board/proportions-1/4d87e664967a0775082939ab/4f1b11c06ce9cdc22617ad2c).

See:

[x is numerator 1.](http://j.mp/xb75F7)
[x is denominator 1.](http://j.mp/xVOnVj)
[x is numerator 2.](http://j.mp/z6tjvf)
[x is denominator 2.](http://j.mp/yHuw3g)