Khan/khan-exercises — Issue #10601: Systems of equations - the  process here is unclear
Author: KhanBugz
Created: 2012-01-07 11:03:40+00:00
State: open
Labels: ie8, ie9, win7, wrong-or-unclear

Reporter: todd.stevenson@yahoo.com

How is 2 times -2y coming out to -y in step two of this problem?

[systems_of_equations.html?seed=108&problem=substitution-x](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/systems_of_equations.html?seed=108&problem=substitution-x&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/systems_of_equations.html?seed=108&problem=substitution-x&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5B%5C%2211%2F6%5C%22%2C%5C%22-7%2F6%5C%22%5D%22%2C104%5D%2C%5B%22incorrect-activity%22%2C%22%5B%5C%2211%2F6%5C%22%2C%5C%227%2F6%5C%22%5D%22%2C149%5D%2C%5B%22hint-activity%22%2C%220%22%2C173%5D%2C%5B%22hint-activity%22%2C%220%22%2C177%5D%2C%5B%22hint-activity%22%2C%220%22%2C178%5D%5D)

[["11/6","-7/6"],["11/6","7/6"]]

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; BRI/2; .NET4.0C)

MathJax is loaded, ready, queue length: 0