用行列式的性质证明：y+z z+x x+y x y z x+y y+z z+x =2 z x y z+x x+y y+z

(x+y-z)(x-y+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) 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) (y-x)/(x+z-2y)(x+y-2z)+(z-y)(x-y)/(x+y-2z)(y+z-2x)+(x-z)(y-z X+Y+Z=? 化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+（z-y)(x-y)/(x-2z+y)(y+z-2x)+(x 1.设有比例式：x/(y+z)=y/(x+z)=z/(x+y),有比例性质,得x/(y+z)=y/(x+z)=z/(x+ x y z x+y--- = --- = ---- ----y+Z z+x x+y ,求 z 的值 .求 x+y---- ①(x+y+z）（-x+y+z）(x-y+z)(x+y-z) 数学 多项式(x+y-z)(x-y+z)-(y+z-x)(z-x-y)公因式 方向 X Y Z (x+y+z)^5-(x+y-z)^5-(x+z-y)^5-(z+y-x)^5,