5x - 2y + 3z = 40 3x + 4y + z = 34 2x + 2y - 4z = -12 tentukan hasil nya dengan cara eliminasi dan campuran

5x - 2y + 3z = 40 .....(1)
3x + 4y + z = 34 ........(2)
2x + 2y - 4z = -12 ......(3)

eliminasi 1 dan 3
5x - 2y + 3z = 40
2x + 2y - 4z = -12
.................................. +
7x - 1z = 28 .......(4)

eliminasi 2 dan 3
3x + 4y + z = 34......(x1)
2x + 2y - 4z = -12....(x2)
sehingga
3x + 4y + z = 34
4x + 4y - 8z = -24
................................... -
-1x+ 9z = 58 ......(5)

eliminasi 4 dan 5
7x - 1z = 28 .....(x1)
-1x+ 9z = 58 .....(x7)
sehingga
7x - 1z = 28
-7x + 63z = 406
................................ +
62z = 434
z = 434/62
z = 7

substitusi z = 7 ke pers (5)
-1x + 9z = 58
x = 9z - 58
x = 9(7) - 58
x = 63 - 58
x = 5

substitusi x = 5 dan z = 7 ke (1)
5x - 2y + 3z = 40
2y = 5x + 3z - 40
2y = 5(5) + 3(7) - 40
2y = 25 + 21 - 40
2y = 6
y = 6/2
y = 3