若x-y+z=-4,x^2-(y+z)^2=8,则x+y+z=
若4x=7y+5z,2x+y=z,则x:y:z的值为
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)(x-y+z)=
若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值
若x-2y+4z=1,x+3y-7z=0,则y:z=?
(x+y-z)^2-(x-y+z)^2=?
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
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)
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-
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
若x/3=y/2=z/5,则2x-3y-z/x-y+z=