Khan/khan-exercises — pull request #7306 by praveenRamalingam (2011-11-29 23:27:11+00:00)
Title: Modify equation of hyperbola exercise to use multiple answer type

Implements

https://trello.com/card/board/modify-equation-of-hyperbola-exercise-to-use-multiple-answer-type/4d87e664967a0775082939ab/4ed471da8cf0c600000f912d