Jika a,b,dan c memenuhi sistem persamaan : 3a+2b-c=2 2a+b-3c =4 a-b+2c =-1 maka nilai a+10b-5c adalah

a+10b-5c = 1 

cara ada pada attach.

Mapel : Matematika
Kelas : X SMA
Bab : SPLTV

Pembahasan :
3a + 2b - c = 2
2a + b - 3c = 4
a - b + 2c = -1

Samakan
2b = 2b
2 + c - 3a = 8 + 6c - 4a
a - 5c = 6

2b = 2b
2a + 4c + 2 = 2 + c - 3a
2a + 4c + 2 = 8 + 4c - 12a
14a = 8 - 2
14a = 6
a = 6/14
a = 3/7

a - 5c = 6
3/7 - 6 = 5c
5c = 3/7 - 42/7
5c = -39/7
c = -39/35

3a + 2b - c = 2
3(3/7) + 2b + 39/35 = 2
9/7 + 39/45 + 2b = 2
45/35 + 39/45 + 2b = 2
84/35 + 2b = 2
2b = 2 - 84/35
2b = 70/35 - 84/35
2b = -14/35
b = -7/35

Hp : {3/7 , -7/35 , -39/35}