SOLUTION: 1 1 2 | 5 2 1 1 | 5 4 0 1 | 5 3 x 3 Matrix - Can not get rid of the 4...

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Question 276629: 1 1 2 | 5
2 1 1 | 5
4 0 1 | 5
3 x 3 Matrix - Can not get rid of the 4...

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
1 1 2 | 5
2 1 1 | 5
4 0 1 | 5
3 x 3 Matrix - Can not get rid of the 4...
=============================
Subtract 2 times 1st row from 2nd
Subtract 4 times 1st row from 3rd
1 1 2 | 5
0 -1 -3 | -5
0 -4 -7 | -15
---------------------
Get rid of the negatives:
1 1 2 | 5
0 1 3 | 5
0 4 7 |15
---------------------------
Subtract 4 times the 2nd from the 3rd
1 1 2 | 5
0 1 3 | 5
0 0 -5 |-5
--------------
Solve the 3rd equation:
z = 1
---
Substitute into the 2nd equation and solve for "y":
y = 2
------
Substitute into the 1st equation and solve for "x":
x = 1
==============
Cheers,
Stan H.

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