数学题{x+2Y+3z=14 2x+y+z=7 3x+y+2z=11
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
x+2y+3z=14 2x+y+z=7 3x+y+2z=11
x+2y+3z=14 2x+y+z=7 3x+y+2z=11 求x y z
数学题{x+2Y+3z=14 2x+y+z=7 3x+y+2z=11
x/2=y/3=z/5 x+3y-z/x-3y+z
三元一次方程组数学题x+2y+2z=33x+y-2z=72x+3y-2z=10x-y=2z-x=3y+z=-1x-y-z
200分求数学题,急x+y-z=-14x-3y+2z=162x-2y-3z=5求z等于多少
x+2y+4z=17 2x+y+z=7 3x+y+2z=11
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?
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
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,