Question 870122
x-2y+z=2
2x-y-z=1 
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You need a 3rd equation if you are going to solve for x,y and z.
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Without a 3rd equation you can solve for one of the variables in 
terms of another::
For example::
z = -x+2y+2
z = 2x -y-1
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Therefore:
-x + 2y +2 = 2x -y -1
3x = 3y + 3
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x = y + 1
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Cheers,
Stan H.
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