resolva

2x + y - 8z = -5
x + y - 2z = 0
x + 2y + 3z = 6

2x + y - 8z = -5
x + y - 2z = 0
x + 2y + 3z = 6

|2 1 -8| 2 1|
|1 1 -2| 1 1|
|1 2 3| 1 2| = 0
D = 6 - 2 - 16 + 8 + 8 - 3
D = 1

|-5 1 -8| -5 1|
| 0 1 -2| 0 1|
| 6 2 3| 6 2| = 0
Dx = - 15 - 12 + 0 + 48 - 20 + 0
Dx = 1

|2 -5 -8|2 -5|
|1 0 -2 |1 0|
|1 6 3 |1 6| = 0
Dy = 0 + 10 - 48 + 0 + 24 + 15
Dy = 1

x = Dx/D
x = 1/1
x = 1

y = Dy/D
y = 1/1
y = 1

x + 2y + 3z = 6

1 + 2 * 1 + 3z = 6
1 + 2 + 3z = 6
3 + 3z = 6
3z = 6 - 3
z = 2 - 1
z = 1