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a bit confused 

 Sep 28, 2019

Best Answer 

 #1
avatar+11689 
+2

 

     1      2      1            5  

     2    - 1     2          15  

     3      1   – 1            8  

 

 The diagonal field of the 1st line is already 1.

 With the 1st row, all other rows in the 1st column are set to 0.

 To the 2nd row the -2-fold of the 1st row is added:

 

     1      2      1          5  

     0    - 5      0          5  

     3      1    - 1          8  

 

 The -3-fold of the 1st line is added to the 3rd line:

 

     1       2       1          5  

     0     - 5      0          5  

     0     - 5    - 4       - 7  

 

 

 

 By dividing the 2nd line by -5 the diagonal element is made to 1:

 

     1     2     1       5  

     0     1     0     - 1  

     0   - 5  - 4     - 7  

 

 With the 2nd row, all other rows in the 2nd column are set to 0.

 

 The 2nd line is added to the 1st line by a factor of -2:

 

     1     0     1       7  

     0    1      0    - 1  

     0  - 5   - 4    - 7  

 

 The 5-fold of the 2nd line is added to the 3rd line:

 

     1     0     1        7  

     0     1     0      - 1  

     0     0   - 4     - 12  

 

 By dividing the 3rd line by -4 the diagonal element is made to 1:

 

     1     0     1        7  

     0     1     0      - 1  

     0     0     1        3  

 

 With the 3rd row, all other rows in the 3rd column are set to 0.

 

 To the 1st line the -1x of the 3rd line is added:

 

     1     0     0       4  

     0     1     0     - 1  

     0     0     1       3  

 

 The last column contains the solutions.


laugh

 Sep 28, 2019
 #1
avatar+11689 
+2
Best Answer

 

     1      2      1            5  

     2    - 1     2          15  

     3      1   – 1            8  

 

 The diagonal field of the 1st line is already 1.

 With the 1st row, all other rows in the 1st column are set to 0.

 To the 2nd row the -2-fold of the 1st row is added:

 

     1      2      1          5  

     0    - 5      0          5  

     3      1    - 1          8  

 

 The -3-fold of the 1st line is added to the 3rd line:

 

     1       2       1          5  

     0     - 5      0          5  

     0     - 5    - 4       - 7  

 

 

 

 By dividing the 2nd line by -5 the diagonal element is made to 1:

 

     1     2     1       5  

     0     1     0     - 1  

     0   - 5  - 4     - 7  

 

 With the 2nd row, all other rows in the 2nd column are set to 0.

 

 The 2nd line is added to the 1st line by a factor of -2:

 

     1     0     1       7  

     0    1      0    - 1  

     0  - 5   - 4    - 7  

 

 The 5-fold of the 2nd line is added to the 3rd line:

 

     1     0     1        7  

     0     1     0      - 1  

     0     0   - 4     - 12  

 

 By dividing the 3rd line by -4 the diagonal element is made to 1:

 

     1     0     1        7  

     0     1     0      - 1  

     0     0     1        3  

 

 With the 3rd row, all other rows in the 3rd column are set to 0.

 

 To the 1st line the -1x of the 3rd line is added:

 

     1     0     0       4  

     0     1     0     - 1  

     0     0     1       3  

 

 The last column contains the solutions.


laugh

Omi67 Sep 28, 2019

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