Khan/khan-exercises — Issue #13546: Expressions with unknown variables 2 - there is better answer
Author: KhanBugz
Created: 2012-02-10 12:56:54+00:00
State: open
Labels: chrome, hard

Reporter: rails@10g.pl

If 5a+6b=6 and 7x+8y+5z=−2,

what is −56y+6b−49x+5a−35z?

=5a+6b−49x−56y−35z

than

(5a+6b) - 7(7x+8y+5z) = 6 - 14 = 8

[expressions_with_unknown_variables_2.html?seed=16&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/expressions_with_unknown_variables_2.html?seed=16&problem=0&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/expressions_with_unknown_variables_2.html?seed=16&problem=0&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5C%228%5C%22%22%2C275%5D%2C%5B%22hint-activity%22%2C%220%22%2C70%5D%5D)

["8"]

Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/535.7 (KHTML, like Gecko) Ubuntu/11.10 Chromium/16.0.912.77 Chrome/16.0.912.77 Safari/535.7

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