Jika penyelesaian sistem persamaan 2x+z=8. y+3z=18 dan 2x+3y-z=18 adalah{(a,b,c)} maka perbandingan nilai a,b,dan c adalah

2x+z = 8 => 2a+c=8
y+3z = 18 => b+3c = 18
2x+3y-z = 18 => 2a+3b-c = 18

2a+c = 8
2a = 8-c
a = (8-c) / 2
a = 4 - c/2

b+3c =18
b = 18-3c

2a+3b-c = 18
2(4- c/2) + 3(18-3c) - c = 18
8-c + 54-9c -c = 18
-11c = 18-8-54
-11c = -44
c = 4

a = 4 - c/2
a = 4 - 4/2
a = 4 - 2
a = 2

b = 18-3c
b = 18-3(4)
b = 18-12
b = 6

a : b : c
= 2 : 6 : 4
= 1 : 3 : 2