6x – 5y + 3z = 23
4x + 8y – 11z = 7
5x – 6y + 2z = 12
Given the equations above, x + y + z = ?
(A) 11
(B) 12
(C) 13
(D) 14
(E) 15
If you do a ton of work trying to solve this, you have missed a crucial shortcut. For strategies and thoughts for solving three equations with three unknowns, as well as a full solution to this particular problem, see:
http://magoosh.com/gmat/2013/gmat-quant ... -unknowns/
Mike![:-)]( "Smile")
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4x + 8y – 11z = 7
5x – 6y + 2z = 12
Given the equations above, x + y + z = ?
(A) 11
(B) 12
(C) 13
(D) 14
(E) 15
If you do a ton of work trying to solve this, you have missed a crucial shortcut. For strategies and thoughts for solving three equations with three unknowns, as well as a full solution to this particular problem, see:
http://magoosh.com/gmat/2013/gmat-quant ... -unknowns/
Mike
