x+y+z=4,x-y+z=0,x-z=8怎么解?

(x+y-z)(x-y+z)= 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))/xyz x分之y+z=y分之z+x=z分之x+y(x+y+z不等于0）,求x+y+z分之x+y-z 分式加减法：已知x+y/z=x+z/y=y+z/x(x+y+z≠0）,求x+y-z/x+y+z 已知x+y/z=x+z/y=y+z/x(x+y+z≠0）,求x+y-z/x+y+z的步骤 已知x+y/z=x+z/y=y+z/x(x+y+z≠0）,求x+y-z/x+y+z的步骤 已知：x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值 X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? 2x+z=10 x+y-z=4 3x-y-z=0 x+y+z=4,x-y+z=0,x-z=8怎么解? (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 已知x+y+z=0求证x*x*x+y*y*y+z*z*z=3xyz 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 x-y-z=0 4x+8y+z=17 z=1 4x-3y-3z=0 x-3y+z=0 并且X Y Z不等于0 求x:z 和y:z的值