已知实数x,y,z满足x+y+z=5,xy+yz+zx=3.求z的取值范围

已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x,y,z,满足那么x+y=6,z^2=xy-9,求(x+y)^z 当x+y+z不等于零,求(x+y)/z的值,并写出一组满足条件的x,y,z的数值.已知x,y,z为实数,x/(y+z)=y/(z+x)=z/(x+y). 已知实数X.Y.Z满足(Y+Z)分之X+(Z+X)分之Y+(X+Y)分之Z=1,则(Y+Z)分之X平方+(Z+X)分之Y平方+(X+Y)分之Z平方的值为（ ） 已知实数x、y、z,满足x+y+z=7, 已知x,y,z为非零实数,且满足x+y-z/z=y+z-x/x=z+x-y/y 求x+y+z/z的值 已知实数x,y,z满足x+y=5,z^2=xy+y-9,那么x+2y+3z=?我很着急 已知实数x,y,z,满足x+y=5,z²=xy+y=9,求x+2y+3Z的值 已知实数x.y.z满足x+y=5及z的2次方=xy+y-9则x+2y+3z=? 已知实数x,y,z满足x+y=5,z^2=xy+y-9,那么x+2y+3z=? 已知实数x、y、z满足x＋y=5,z的平方=xy+y-9,那么x+2y+3z=( ) 已知实数x,y,z满足x-y=5,z^2=-xy-y-9,求x-2y+3z的值 已知实数xyz满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3求x+y+z的值 已知实数x,y,z满足关系式2x-3y-z=0,x-2y+z=0,求x比y比z的值 已知x,y,z均为实数,且满足:x+2y-z=6,x-y+2z=3.求x+y+z的最小值 已知实数 x y z 满足x+y-z=0 ,3x-y+2z=0 则x :y :z 已知三个实数x,y,z满足条件(z-x)^2-4(x-y)(y-z)=0,求证:x,y,z成等差数列