已知x^2+y^2+2z^2-2x+4y+4z+7=0,则xyz=?

已知：x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 已知整数x、y、z,满足x≤y＜z,且｜x+y｜+｜y+z｜+｜z+x｜=4,｜x-y｜+｜y-z｜+｜z-x｜=2,求x^2+y^2+z^2的值. 已知整数x,y,z满足x≤y＜z,且|x+y|+|y+z|+|z+x|=4 |x-y|+|y-z|+|z-x|=2 那么x²+y²+z²的值 已知XY=2(X+Y),YZ=4(Y+Z),ZX=5(Z+X),求X,Y,Z已知XY=2(X+Y),YZ=4(Y+Z),ZX=5(Z+X),求X,Y,Z 已知x/2=y/3=z/4,则2x+y-z/3x-2y+z=? 已知(x+2y)/2=(y+3z)/3=(z+4x)/4,则x:y:z=? 已知x+4y+z=24,2x+7y=2z=41,求x+y+z 已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z 已知X+4Y+Z=24,2X+7Y+2Z=41,则x:y:z= 已知2x-y-z=0,3x+4y-2z=0,则x：y：z=? 已知(x-z)^2-4(x-y)(y-z)=0,求证：2y=x+z 已知x/3=y/4=z/2,求x+2y-z/x+y+z=? 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 已知x+4y-3z=0,4x-5y+2z=0,则x：y：z 已知x+4y=3z,4x-5y=-2z,则x:y:z 已知X:Y:Z=3:4:5,求4X+3Y-2Z/X+Y+Z的值 化简(x+Y)^2(y+z-x)(z+x-y)+(x-y)^2(x+y+z)(x+y-z)