{x+y+z=18 (1)
{8x+6y+6z=112 (2)
{2y+z=22(3)
(2)-(1)×6得
8x-6x=112-18×6
2x=4
x=2
将x=2代入（2）得
6y+6z=112-2*8
6y+6z=96
y+z=16(4)
(3)-(4)得
y=6
将y=6代入4得出
z=10
所以解得
{x=2
{y=6
{z=10