Khan/khan-exercises — pull request #58449 by petercollingridge (2013-08-06 10:52:43+00:00)
Title: Adding and subtracting rational expressions 6

Based on: https://www.khanacademy.org/math/algebra/rational-expressions/rational_expressions/v/adding-and-subtracting-rational-expressions

Required quite a lot of computation to solve. Sometimes I can't work out what answer the editor will accept as correct. Would be nice to not use data-simplify, but if it's not included then typing the question is accepted as a correct answer.