SOLUTION: please help solve http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=178098 thanks!

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Question 178052: please help solve

http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=178098

thanks!
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
2x+y+z=-2
2x-2y+3z=6
3x-5y+4z=7
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Eliminate x. Multiply 1 and 2 by 3, and eqn 3 by -2
6x + 3y + 3z = -6
6x - 6y + 9z = 18
-6x + 10y - 8z = -14
ADD eqn 3 to 1 and to 2
6x + 3y + 3z = -6
-6x + 10y - 8z = -14
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13y - 5z = -20 (eqn 4)
Add again
6x - 6y + 9z = 18
-6x + 10y - 8z = -14
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4y + z = 4 (eqn 5)
Multiply eqn 5 by 5 and add to eqn 4
13y - 5z = -20 (eqn 4)
20y + 5z = 20 Add these 2
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33y = 0
y = 0 yyyyyyyyyyyyyyyyyy
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4y + z = 4 (eqn 5)
z = 4 zzzzzzzzzzzzzzzzzzzz
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2x+y+z=-2 Original eqn
2x+0+4 = -2
x = -3 xxxxxxxxxxxxxxxxxxxx