x+2y-3z=-4 2x-y+z=3 3x+2y+z=10. carilah nilai x,y,z dengan menggunakan metode gabungan

x + 2y - 3z = -4 .... (1)
2x - y + z = 3 ... (2)
3x + 2y + z = 10 ... (3)

El. y (1) & (3)
x + 2y - 3z = -4
3x + 2y + z = 10
---------------------- (-)
-2x - 4z = -14 .... (4)

El. y (1) & (2)
x + 2y - 3z = -4
2x - y + z = 3
----------------------
x + 2y - 3z = -4
4x - 2y + 2z = 6
----------------------- (+)
5x - z = 2 .... (5)

El z (4)&(5)
-2x - 4z = -14
5x - z = 2
--------------------
-2x - 4z = -14
20x - 4z = 8
-------------------- (-)
-22x = -22
x = 1

El. x (4)&(5)
-2x - 4z = -14
5x - z = 2
-------------------
-10x - 20z = -70
10x - 2z = 4
-------------------- (+)
-22z = -66
z = 3

Subs x = 1, z = 3 ke (1)
x + 2y - 3z = -4
1 + 2y - 3(3) = -4
1 + 2y - 9 = -4
2y - 8 = -4
2y = -4 + 8
2y = 4
y = 4/2
y = 2

x = 1
y = 2
z = 3

Uji (1)
x + 2y - 3z = -4
1 + 2(2) - 3(3) = -4
1 + 4 - 9 = -4
-4 = -4 ✔