（1）{x+2y+3z=14① {2x+y+z=7②{3x+y+2z=11③（2）{x-3/2+3≥x+1①{1-3(x-1)1+2x①{3x+2

x+y+z=6 x+2y+3z=14 y+1=z (1)X+Y=15,Y+Z=-6,Z+X=7.(2)X+Y=-14,Y+Z=-7,Z+X=9.(3)X+Y=0,Y+Z=-1,Z+X=-1. 已知xyz≥0,x+y+z=1,化简x（2y-z）/(1+x+3y)+y(2z-x) /(1+y+3z) +z(2x-y)/(1+z+3x) 3x+2y+z=14 x+y+2z+-3 2x+3y-z=1 [3x+2y+z=14,x+y+z=10,2x+3y-z=1] 3x+2y+z=14 { x+y+z=10 2x+3y-z=1 3x+2y+z=14 ,x+y+z=10,z+2x+3y=1 5 解方程：x+z=y (1) ,7z-(x+y)=2 (2) ,x+y+z=14 (3) 已知（1）X-Y+Z=0 (2)X+2Y-3Z=0 求X:Y:Z 已知x/2=y/3=z/4,求下列各式 （1）(x+y+z)/x (2)(x-y+2x/(x-y-2z) 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 解三元一次方程组 ①2x-y+z=1 3x+y -2z=2 X+2y-z=3 ②x-4y+z=-3 2x+Y-Z=18 X-Y-Z=7 ③4x+4y+2z=7 6X-4y-z=6 2x-y+z=1 已知x:：y：z=3：4：5,(1)求x+y分之z的值；（2）若x+y+z=6,求x,y,z. 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 解三元一次方程组.速回.（1）X+Y+Z=25 X-Y=1 2X+Y-Z=18（2）X-Y-Z=0 X+Y-3Z=4 2X+3Y-5Z=14（3） X-2Y=-9 Y-Z=3 2Z+x=47（4）3X-y+z=4 2X+3Y-Z=12 X+Y+z=-28（5）4X+9Y=13 3y-2Z=-1 7X+5Z=17速回 我会奖励积分 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值