| 
 
 
 
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. 
 
  | 
 
  
 
 |   
 
 |   
 |  |