Khan/khan-exercises — Issue #13558: Number properties terminology 1 - hard
Author: KhanBugz
Created: 2012-02-10 15:32:10+00:00
State: open
Labels: firefox, hard, snowleo

this is so confuseing

[number_properties_terminology_1.html?seed=20&problem=commutative-variable](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/number_properties_terminology_1.html?seed=20&problem=commutative-variable&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/number_properties_terminology_1.html?seed=20&problem=commutative-variable&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5C%22%3Ccode%20style%3D%5C%5C%5C%22display%3A%20none%3B%5C%5C%5C%22%3Ea%2B(b%2Bc\)%3D(a%2Bb\)%2Bc%3C%2Fcode%3E%5C%22%22%2C6%5D%5D)

["a+(b+c)=(a+b)+c"]

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13

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