1,{2x+y+z=-26,x+2y+z=-30,x+y+2z=-28 2,{5x+2y+z=12,4x+3y+z=13
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
1,{2x+y+z=-26,x+2y+z=-30,x+y+2z=-28 2,{5x+2y+z=12,4x+3y+z=13
x/2=y/3=z/5 x+3y-z/x-3y+z
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
已知 x,y,z都是正实数,且 x+y+z=xyz 证明 (y+x)/z+(y+z)/x+(z+x)/y≥2(1/x+1
(x+y-z)^2-(x-y+z)^2=?
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
x,y,z为实数 且(y-z)^2+(x-y)^2+(z-x)^2=(y+z-2x)^2+(x+z-2y)^2+(x+y
分解因式:f(x,y,z)=x^2(y-z)+y^2(z-x)+z^2(x-y)
1.x+y+z=21,x-y=1,2x+z-y=13.2.3x+2y+z=13,x+y+2z=7 ,2z+3y-z=12
x,y,z为实数且(y-z)平方+(x-y)平方+(z-x)平方=(y+z-2x)平方+(z+x-2y)平方+(x+y-