x,y,z∈R*,x-2y+3x=0,y^2/xz的最小值为

已知x,y,z∈ R,x+2y=z+6,x-y=3-2z,求x^2+y^2+z^2的最小值. x,y,z∈R*,x-2y+3x=0,y^2/xz的最小值为 已知x,y,z∈R,求证:x^2+y^2>=xy+x+y-1 设x,y,z∈R,2x+2y+z+8=0,则(x-1)^2+(y+2)^2+(z-3)^2最小值 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 设x,y,z∈,R求证：x²+xz+z²+3y(X+y+z)≥0 一道函数不等式题求出所有这样的函数f:R-R,使得对于一切x,y,z∈R,有f(x+y)+f（y+z）+f(x+z)=3f(x+2y+3z)f(x+y)+f（y+z）+f(x+z)=3f(x+2y+3z)改为f(x+y)+f（y+z）+f(x+z)≥3f(x+2y+3z) x,y,z属于R,x-2y+3z=0,y^2/xz的最小值是? 已知x,y,z属于R+,x-2y+3z=0,则(y平方)/(xz)的最小值为? 已知x,y,z∈R+,且x+y+z=3,求证：x^2/（y^2+z^2+yz）+y^2/(x^2+z^2+zx）+z^2/(x^2+y^2+xy)≥1 证明 已知xyz∈R^+, x^2x * y^2y* z^2z≥x^y+x* y^z+x * z^x+y 若x,y,z∈R,且x+y+z=xyz,求证：(y+z)/x+(z+x)/y+(x+y)/z≥2(1/x+1/y+1/z)^2 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 若x,y,z∈R+,且x+y+z=xyz,求证:(y+z)/x+(z+x)/y+(x+y)/z＞2(1/x+1/y+1/z) 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 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 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. 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