Answer:
(1, 0, 2)
Step-by-step explanation:
[3 -1 2 | 7 ]
|6 -10 3 | 12|
[1 -1 4 | 9 ]
To the first row, add -3 times the values of the third row
To the second row, add -6 times the values of the third row
[0 2 -10 | -20 ]
|0 -4 -21 | -42 |
[1 -1 4 | 9 ]
To the second row, add 2 times the values in the first row
[0 2 -10 | -20 ]
|0 0 -41 | -82 |
[1 -1 4 | 9 ]
z = -82 / -41
z = 2
2y - 10(2) = -20
y = 0
x - 0 + 4(2) = 9
x = 1
