已知x、y、z是正整数,求解下列联立方程 (x-y)(y-z)(z+x)=-90 (x-y)(y+z)(z-x)=42
(x+y-z)(x-y+z)=
X+Y+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+y-z)/z=(x-y+z)/y+(y+z-x)/x,且xyz≠0,求代数式[(x+y)(y+z)(x+z)
x,y,z正整数 x>y>z证明 x^2x +y^2y+z^2z>x^(y+z)*y^(x+z)*z^(x+y)
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/(
f(x,y,z,w)=x*(x+y)*(x+y+z)*(x+y+z+w)
已知 x/(y+z)+y/(z+x)+z/(x+y)=1
已知x,y,z是正整数,且x大于y,x+y=6,z-y=2000,求x+y+z的最大值,要求:分类讨论
已知三个正整数x,y,z满足x+y+z=xyz,且x
x y z x+y--- = --- = ---- ----y+Z z+x x+y ,求 z 的值 .求 x+y----