SOLUTION: 2x+2y+2z=0 -2x+5y+2z=1 8x+y+4z=-1 by using gauss Jordan elimination methid

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Question 982652: 2x+2y+2z=0
-2x+5y+2z=1
8x+y+4z=-1 by using gauss Jordan elimination methid

Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
 2x+2y+2z=0
-2x+5y+2z=1
 8x+y+4z=-1

Get rid of the -2x by adding the 1st equation to the 2nd equation:

 2x+2y+2z=0
   +7y+4z=1
 8x+y+4z=-1

Get rid of the 8x by multiplying the 1st equation by -4 then 
adding it to the 3rd equation:

-8x-8y-8z=0
   +7y+4z=1
 8x+y+4z=-1

-8x-8y-8z=0
   +7y+4z=1
   -7y-4z=-1

Then divide the 1st equation through by -8

  x+ y+ z=0
   +7y+4z=1
   -7y-4z=-1

Get rid of the -7y by adding the 2nd equation to the 3rd equation

  x+ y+ z=0
   +7y+4z=1

The whole 3rd equation vanished when I did that.

Solve the second equation for y

  7y+4z=1
     7y=1-4z
      y=1%2F7-expr%284%2F7%29z

Substitute in the first equation:

  x + 1%2F7-expr%284%2F7%29z + z=0
  x + 1%2F7-expr%284%2F7%29z%2Bexpr%287%2F7%29z=0
  x + 1%2F7%2Bexpr%283%2F7%29z=0
  x = -1%2F7-expr%283%2F7%29z
 
General solution:

%28matrix%281%2C5%2Cx%2C%22%2C%22%2Cy%2C%22%2C%22%2Cz%29%29%22%22=%22%22

Edwin