x+y+z=0,3x-2y-2z=5,y-z=2x-7
x/2=y/3=z/5 x+3y-z/x-3y+z
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
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4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
x+y-z=0 2x-3y+2z=5 x+2y-z=3
解三元一次方程:x+y-z=0,2x+y+z=7,x-3y+z=8
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z