Khan/khan-exercises — Issue #4813: Systems of equations - Systems of Equations Practice Question - I think the answer  required is incorrect.
Author: KhanBugz
Created: 2011-10-22 20:05:31+00:00
State: open
Labels: firefox, vista

Reporter: awb_1@hotmail.com

Solve for x and y using elimination.

−3x+6y−8x−6y=9=−6

We can eliminate y when its corresponding coefficients are negative inverses.

Add the top and bottom equations.

−11x=3

Divide both sides by −11 and reduce as necessary.

x=−3/11

Substitute −3/11 for x in the top equation.

−3(−3/11)+6y=9

9/11+6y=9

6y=90/11 ***should be 6y+99/11***

y=15/11 ***y should be 11/6***

x=−311,y=1511

[systems_of_equations.html?seed=53&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/systems_of_equations.html?seed=53&problem=0&debug)

[["-3/11","11/6"],["-3/11","11/6"]]

Mozilla/5.0 (Windows NT 6.0; rv:7.0.1) Gecko/20100101 Firefox/7.0.1

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