x、y、z>0,2x+3y+5z=6,求x^2yz最大值
f(x,y,z)=yz+xz使得,y^2+z^2=1,yz=3,求f最大值
若实数x,y,z满足x+y+z=5,xy+yz+xz=3,求z的最大值
时数x,y,z满足x+y+z=5,xy+yz+zx=3,求Z最大值
x+3y+7z=0 2x+5y+11z=0,求(x^2+y^2+z^2)/(xy+2yz+3xz)
已知4x-5y+2z=0,x+4y-3z=0,求(x²+y²+z²)/xy+yz+xz
x,y,z是三个不全为0的实数,求(xy+2yz)/(x+y+z)的最大值
若|x-3|+|y+z|+|2z+1|=0,求xy-yz的值
已知x yz不等于0且x+3y+z=0 2x+3y-z=0求3x+5y+z分之x+2y-7z的值
x+y+z=5,xy+xz+yz=1 ,求Z的最小值和最大值
已知2X-3Y-Z=0,X+3Y-14Z=0,X,Y,Z不全为0,求【4X的平方-5XY+Z的平方】除以【XY+YZ+Z
已知三个数x,y,z,满足xy/x+y=-2,yz/y+z=4/3,zx/z+x=-4/3,求(xyz)/(xy+yz+
x/3=y/2=z/5,求xy+yz+xz/x²+y²+z²