tentukan niai 2a - b - c jika diketahui SPLTV: 2a - 3b + c = 19 3a + 2b - 2c = 2 a - 4b - c =14 tolong dijawab

2a - 3b + c = 19
3a + 2b - 2c = 2
a - 4b - c = 14

a - 4b - c = 14
a = 14 + 4b + c

2a - 3b + c = 19
2(14 + 4b + c) - 3b + c = 19
28 + 8b + 2c - 3b + c = 19
5b + 3c = 19 - 28
5b + 3c = - 9

3a + 2b - 2c = 2
3(14 + 4b + c) + 2b - 2c = 2
42 + 12b + 3c + 2b - 2c = 2
14b + c = 2 - 42
14b + c = - 40

5b + 3c = - 9|× 1
14b + c = - 40|× 3

5b + 3c = - 9
42b + 3c = - 120
____________ —
- 37b = 111
b = - 3

5b + 3c = - 9
- 15 + 3c = - 9
3c = - 9 + 15
3c = 6
c = 2

a = 14 + 4b + c
a = 14 - 12 + 2
a = 2 + 2
a = 4

2a - b - c
= 8 + 3 - 2
= 11 - 2
= 9

Maaf Kalau Salah