已知（Y+Z）/X=(Z+X)/Y=(X+Y)/Z(X+Y+Z≠0)求分式（X+Y-Z）/(X+Y+Z)的值

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/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? 已知x>0,y>0,z>0.求证（y/x+z/x）（x/y+z/y)(x/z+y/z）>=8 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求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 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+y-z)(x-y+z)= 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x+y+z=0求证x*x*x+y*y*y+z*z*z=3xyz 已知(y+z)/x=(z+x)/y=(x+y)/z,则(y+z)/x的值是多少 已知X+Y+Z=0,求（X+Y)(Y+Z)(X+Z)+XYZ的值. 已知x+y+z=0,求(x+y)(y+z)(z+x)+xyz的值 已知x+y+z=0,求(x+y)(y+z)(x+z)+xyz的值 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 已知x,y,z>0,xyz(x+y+z)=1,求证（x+y）(x+z)>=2 已知x/(y+z+u)=y/(z+u+x)=z/(u+x+y)=u/(x+y+z)求(x+y)/(z+u)+(y+z)/(x+u)+(z+u)/(x+y)+(u+x)/(y+z)