Question

Solve the System
3x-y=9
2y+z=8
x+4z=12

Answer 1

1 0 4 12
0 2 1 8
3 -1 0 9

Answer 2

subtract 3*row 1 from row 3

Answer 3

1 0 4 12
0 2 1 8
0 -1 -12 -27

Answer 4

add 2*row 3 to row 2

Answer 5

1 0 4 12
0 0 -23 -46
0 -1 -12 -27

Answer 6

z = -46/-23 = 2

Answer 7

x + 4z = 12
x = 12 - 4(2) = 4

Answer 8

-y -12z = -27
y = 27 - 12(2) = 3

Answer 9

x = 4
y = 3
z = 2