2x+y+z=17 2y+x+z=17 2z+x+y=17 怎么算?
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
x+2y+4z=17 2x+y+z=7 3x+y+2z=11
2x+y+z=17 x+2z+y=14 x+z+2y=13 求:xyz
2x-y+2z=-17 3x+y-3z=-4 x+y+z=6
解方程组:2x+y+z=15 x+2y+z=16 x+y+z=17
(x+y-z)^2-(x-y+z)^2=?
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-9z=17 3x+y+15z=18 x+2y+3z=2
4X-9Z=17 3X+Y+15Z=18 X+2Y+3Z=2
{4x-9z=17{3x+y+15z=18{x+2y+3z=2