设x,x,z属于R,且x+5y+9z=160求证|x+2y+2z|+3|y+z|+4|z|》160
设x,y,z 都属于R,且(x-z)²-4(x-y)(y-z)=0,求证:x,y,z成等比数列.
设x,y,z属于R且3^x=4^y=6^z
已知x,y,z属于R+(正实数),且xyz(x+y+z)=4+2*根号下3,则(x+y)(y+z)的最小值是?
设x,y,z∈R+,且3x=4y=6z.
设 x,y∈R ,且3^x=4^y=6^z,求证 1/z - 1/x =1/2y .
设x,y属于R且3^x=4^y=6^z,求1/z-1/x-1/2y
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
设x、y、z为整数,证明:x^4*(y-z)+y^4*(z-x)+z^4*(x-y)/(y+z)^2+(z+x)^2+(
已知x,y,z都是正数,且xyz=1,求证:x^2/(y+z)+y^2/(x+z)+z^2/(x+y)≥3/2
已知xyz属于R+,x+y+z=1,求证x^3/(y(1-y))+y^3/(z(1-z))+z^3/(x(1-x))大于
x/2=y/3=z/5 x+3y-z/x-3y+z
x,y,z属于正实数,且3x+4y+5z=1 求1/(x+y)+1/(y+z)+1/(x+z)的最小值