3x-y+z=3,2x+3y-z=12,x+y+z=6
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
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
1.x+y=16,y+z=12,z+x=102.3x-y+z=4,2x+3y-z=12,x+y+z=63.x+y+z=6
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
①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z-
已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3
若{x+3y+10z=0 则 (x+y-z)/(x-y+z)
3x-y+z=3 2x+y-3z=11 x+y+z=12 解方程
x+y+z=4 2x+3y-z=6 3x+2y+2z=10