Question

Diberikan SPLTV :
3a - b + 2c = 16
2a + b + c = 1
4a + 2b + c = 18

nilai a - b + c = ....
tolong dbantu

Answer 1

3a - b + 2c = 16
2a + b + c = 1
-------------------(+)
5a + 3c = 17
2a + b + c = 1|x2|4a + 2b + 2c = 2
4a + 2b + c = 18|x1|4a + 2b + c = 18
------------------------------------(-)
c = - 16
5a + 3c = 17
5a + 3.(-16) = 17
5a - 18 = 17
5a = 17 + 18
5a = 35
a = 35 : 5 = 7
3a - b + 2c = 16
3.7 - b + 2.(-16) = 16
21 - b - 32 = 16
-b = 16 + 11
b = - 27