若X+Y-Z=11,Y+Z-X=5,Z+X-Y=1,则X+Y+Z=?
(x+y-z)(x-y+z)=
X+Y+Z=?
若z分之x+y+z=y分之x-y+z=x分之-x+y+z,求xyz分之(x+y)(y+z)(z+x)
若{x+3y+10z=0 则 (x+y-z)/(x-y+z)
f(x,y,z,w)=x*(x+y)*(x+y+z)*(x+y+z+w)
已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/
已知实数x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求x2/(y+z)+y2/(z+x)+z2/(
x y z x+y--- = --- = ---- ----y+Z z+x x+y ,求 z 的值 .求 x+y----
x/2=y/3=z/5 x+3y-z/x-3y+z
已知 x/(y+z)+y/(z+x)+z/(x+y)=1
x+y+z=1 求xyz/(x+y)(y+z)(z+x)的最大值
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