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| Question 34772:  Solve the following system of equations using Gaussian elimination (with a matrix) and back substitution, or by using Gauss-Jordan elimination.
 3x + y - z = 0
 x + y = 2z = 6
 2x + 2y = 3z = 10
 Found 2 solutions by  checkley71, richwmiller:
 Answer by checkley71(8403)
      (Show Source): Answer by richwmiller(17219)
      (Show Source): 
You can put this solution on YOUR website! if you mean 3,1,-1,0
 1,1,+2,6
 2,2,+3,10
 divide row 1 by 3/1
 1,1/3,-1/3,0
 1,1,2,6
 2,2,3,10
 
 
 add  down (-1/1) *row 1 to row 2
 1,1/3,-1/3,0
 0,2/3,7/3,6
 2,2,3,10
 
 
 add  down (-2/1) *row 1 to row 3
 1,1/3,-1/3,0
 0,2/3,7/3,6
 0,4/3,11/3,10
 
 
 divide row 2 by 2/3
 1,1/3,-1/3,0
 0,1,21/6,9
 0,4/3,11/3,10
 
 
 add  down (-4/3) *row 2 to row 3
 1,1/3,-1/3,0
 0,1,7/2,9
 0,0,-1,-2
 
 
 divide row 3 by -1/1
 1,1/3,-1/3,0
 0,1,7/2,9
 0,0,1,2
 
 
 add up  (-7/2) *row 3 to row 2
 1,1/3,-1/3,0
 0,1,0,2
 0,0,1,2
 
 
 add up  (1/3) *row 3 to row 1
 1,3/9,0,2/3
 0,1,0,2
 0,0,1,2
 
 
 add up  (-1/3) *row 2 to row 1
 1,0,0,0
 0,1,0,2
 0,0,1,2
 
 final
 1,0,0,0
 0,1,0,2
 0,0,1,2
 
 1,0,0,0
 0,1,0,2
 0,0,1,2
 if you mean
 3,1,-1,0
 1,1,-2,6
 2,2,-3,10
 
 divide row 1 by 3/1
 1,1/3,-1/3,0
 1,1,-2,6
 2,2,-3,10
 
 
 add  down (-1/1) *row 1 to row 2
 1,1/3,-1/3,0
 0,2/3,-5/3,6
 2,2,-3,10
 
 
 add  down (-2/1) *row 1 to row 3
 1,1/3,-1/3,0
 0,2/3,-5/3,6
 0,4/3,-7/3,10
 
 
 divide row 2 by 2/3
 1,1/3,-1/3,0
 0,1,-15/6,9
 0,4/3,-7/3,10
 
 
 add  down (-4/3) *row 2 to row 3
 1,1/3,-1/3,0
 0,1,-5/2,9
 0,0,1,-2
 
 
 divide row 3 by 1/1
 1,1/3,-1/3,0
 0,1,-5/2,9
 0,0,1,-2
 
 
 add up  (5/2) *row 3 to row 2
 1,1/3,-1/3,0
 0,1,0,4
 0,0,1,-2
 
 
 add up  (1/3) *row 3 to row 1
 1,3/9,0,-2/3
 0,1,0,4
 0,0,1,-2
 
 
 add up  (-1/3) *row 2 to row 1
 1,0,0,-2
 0,1,0,4
 0,0,1,-2
 
 final
 1,0,0,-2
 0,1,0,4
 0,0,1,-2
 
 1,0,0,-2
 0,1,0,4
 0,0,1,-2
 
 
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