已知:x-y+z=0,x+y-5z=0,xyz≠0,求x²+y²+z²/2x²+

已知：(x+y-z)/z=(x-y+z)/y+(y+z-x)/x,且xyz≠0,求代数式[(x+y)(y+z)(x+z) 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 已知x-2y+z=0,3x+6y-z=0(xyz≠0),求2x²+y²/x²+y² 数学题已知xyz≠0,且x+y+z=1,x²+y²+z²=1,求1/x+1/y+1/z的值 已知x+y-7z=0 x-2y+5z=0(xyz不等于0）,求x+2y-z/y-2x+12z 已知4x-5z=y-x+6z=x+y+z,xyz≠0,求x：y:：z 已知4x+5y-7z=0 x+2y-z=0,且xyz≠0,试求x²+2y²-6z²/2x& 已知有理数x,y,z满足(x-z-2)²+(3x-6y-7)+|3y+3z-4|=0,则xyz= 已知:(x+y)/z=(x+z)/y=(z+y)/x,且xyz不等于0,则分式(x+y)(x+z)(z+x)/xyz的值 已知x²+y²+z²-2x+4y-6z+14=0,求x+y-z/x+y+z的值 已知x,y,z满足x+y+2z=1,x²+y²+6z+1.5=0,求x,y,z的值 若xyz不等于0,且满足(y+z)/x=(x+z)/y=(x+y)/z,求（y+z)（x+z)（x+y)/xyz的值