Khan/khan-exercises — pull request #58407 by petercollingridge (2013-08-05 14:02:24+00:00)
Title: Adding and subtracting rational expressions 5

Adding and subtracting two expressions with different denominators, where each is of the form (Ax + B) / (Cx + D).
Quite nasty and some answers may cancel in ways I haven't anticipated. The expression editor might be able to deal with this, but I have included data-simplify to avoid people merely typing in the question.