Khan/khan-exercises — Issue #8409: Adding and subtracting polynomials - I think this is wrong 
Author: KhanBugz
Created: 2011-12-12 10:35:56+00:00
State: open
Labels: chrome, win7, wrong-or-unclear

Reporter: jone11@ru.is

it look like there is a wrong answer

(5a^5−6a^3)−(2a^5−3a^3)
3a^5-9a^3 ?

best regrets from Iceland

Jón Heiðar

[adding_and_subtracting_polynomials.html?seed=85&problem=subtract](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/adding_and_subtracting_polynomials.html?seed=85&problem=subtract&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/adding_and_subtracting_polynomials.html?seed=85&problem=subtract&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5C%22None%20of%20the%20above.%5C%22%22%2C25%5D%2C%5B%22incorrect-activity%22%2C%22%5C%22%3Ccode%20style%3D%5C%5C%5C%22display%3A%20none%3B%20%5C%5C%5C%22%3E7a%5E%7B5%7D-9a%5E%7B3%7D%3C%2Fcode%3E%5C%22%22%2C19%5D%2C%5B%22incorrect-activity%22%2C%22%5C%22%3Ccode%20style%3D%5C%5C%5C%22display%3A%20none%3B%20%5C%5C%5C%22%3E-5a%5E%7B5%7D-3a%5E%7B3%7D%3C%2Fcode%3E%5C%22%22%2C3%5D%2C%5B%22correct-activity%22%2C%22%5C%22%3Ccode%20style%3D%5C%5C%5C%22display%3A%20none%3B%20%5C%5C%5C%22%3E3a%5E%7B5%7D-3a%5E%7B3%7D%3C%2Fcode%3E%5C%22%22%2C7%5D%5D)

["None of the above.","7a^{5}-9a^{3}","-5a^{5}-3a^{3}","3a^{5}-3a^{3}"]

Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.121 Safari/535.2

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