x=1,y=2,z=3; x=y--

试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) x+2y=3 x+y+z=36 2x+y+z=15 2y=3z x-y=1 x+2y+z x-z=-1 2x+z-y=1 x/2=y/3=z/5 x+3y-z/x-3y+z (x+y-z)(x-y+z)= 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 3道高数题,1,函数F(x,y,z)=(e^x) * y * (z^2) ,其中z=z(x,y)是由x+y+z+xyz= 如果,根号x-3+| y-2 |+z^2=2z-1 求 （x+z)^y 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 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 X+Y+Z=352X=Y+51/3Y=1/2Z {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,