(X+Y+Z=17;2X-Y-2Z=1;3X+Y-4Z=3.)怎样解

来源：学生作业帮编辑：作业帮分类：综合作业时间：2024/06/06 21:28:47

(X+Y+Z=17;2X-Y-2Z=1;3X+Y-4Z=3.)怎样解
用三元一次方程解

X+Y+Z=17; 1)
2X-Y-2Z=1; 2)
3X+Y-4Z=3 3)
1)+2),得3X-Z=18 4)
2)+3),得5X-6Z=4 5)
4)×6-5）,得
13X=104
X=8
代入4）,得
Z=6
将X,Z代入1）,得
Y=3

试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, x/2=y/3=z/5 x+3y-z/x-3y+z x+2y+4z=17 2x+y+z=7 3x+y+2z=11 2x-y+2z=-17 3x+y-3z=-4 x+y+z=6 解方程组：x-2y+z=-1,x+y+z=2,x+2y+3z=-1 解方程：{2x+3y+z=7,x+y+z=4,3x+y-z=-4 x+y+z=2 4x+2y+z=4 2x+3y+z=1 解方程组{3x+y-z=4,2x-y+3z=12,x+y+z=6} 解方程{3x -y+z=4 2x+3y-z=12 x+y+z=6 解方程组x-4y+z=-3,2x+y-z=18,x-y-z=7. x+y/2=z+x/3+y=z/4,...x+y+z=27.解方程组.