tolong bantu jawab...
SPLTV
x + 2y + z = 8 ....(1)
2x - y + 2z = 6 ....(2)
x + 3y - z = 4 ....(3)
- Ubah bentuk pers. (1)
x + 2y + z = 8
x + z = 8 - 2y
x = 8 - 2y - z ...(4)
- Substitusi kan pers. (4) ke pers. (2)
2x - y + 2z = 6
2(8 - 2y - z) - y + 2z = 6
16 - 4y - 2z - y + 2z = 6
16 - 5y = 6
-5y = 6 - 16
-5y = -10
y = 10/5
y = 2
- Substitusi pers. (4) ke pers. (3)
x + 3y - z = 4
8 - 2y - z + 3y - z = 4
y - 2z = -4 ....(5)
- Substitusi nilai y ke pers. (5)
y - 2z = -4
2 - 2z = -4
-2z = -4 - 2
-2z = -6
z = 6/2
z = 3
- Substitusi nilai z dan y ke pers. (4)
x = 8 - 2y - z
x = 8 - 2(2) - 3
x = 8 - 4 - 3
x = 4 - 3
x = 1
- Nilai 2x + 3y - z
2x + 3y - z
= 2(1) + 3(2) - 3
= 2 + 6 - 3
= 8 - 3
= 5 (E.)
