2x+y+z=17 x+2z+y=14 x+z+2y=13 求:xyz

2x+y+z=17 x+2z+y=14 x+z+2y=13 求:xyz 设X+Y+Z=0求X^3+X^2Z-XYZ+Y^2Z+Y^3的值 x*x+y*y+2z*z-2x+4y+4z+7=0,求xyz的值 已知 x,y,z都是正实数,且 x+y+z=xyz 证明 (y+x)/z+(y+z)/x+(z+x)/y≥2(1/x+1 已知x+y-z/z=x-y+z/y=-x+y+z/x,且xyz不等于0,求分式[(x+y)(x+z)(y+z)]/xyz x:y:z=2:3:4且x+y+z=18求xyz 方程组X:Y:Z=4:7:8,X+Y+2Z=54 求XYZ 方程组:x-2y+4z=0,2x+3y-3z=0...xyz不等于0,求(2x+y-z)\(2x-y+z) 已知x+y-7z=0 x-2y+5z=0(xyz不等于0）,求x+2y-z/y-2x+12z 已知xyz不等于0,且x+2y-z=0,7x-y-z=0,求x+y+z/2x-y-z的值. 已知4x-3y+z=0,x+2y-8z=0,xyz不等于0,求x+y-z/x-y+2z的值 已知XYZ满足方程组 X+Y-Z=6 Y+Z-X=2 Z+X-y=0 求X Y Z的值