x+y+z=26,x-y+z=8,2x-y+z=18
(x+y-z)(x-y+z)=
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)
(x+y-z)^2-(x-y+z)^2=?
已知x+2y-z=8,2x-y+z=18 ,求8X+Y-Z的值
f(x,y,z,w)=x*(x+y)*(x+y+z)*(x+y+z+w)
解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18
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)^2+(x-y)^2+(z-x)^2=(y+z-2x)^2+(x+z-2y)^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-
x/2=y/3=z/5 x+3y-z/x-3y+z
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2