xy(x^2-y^2)+yz(y^2-z^2)+zx(z^2-x^2)据说是轮换对称式,分解因式

(2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ) 化简(2x-y-z/x^2-xy-xz+yz)+(2y-x-z/y^2-xy-yz+xz)+(2x-x-y/z^2-xz-yz+xy) 化简x^2-yz/[x^2-(y+z)x+yz]+y^2-zx/[y^2-(z+x)y+zx]+z^2-xy/[z^2-(x+y)z+xy] 求(2X+Z-Y)/(X^2-XY+XZ-YZ)-(2X+Y+Z)/(X^2+XY+XZ+YZ) 分式题:xy=x+y,yz=2(y+z),zx=3(z+x),求xyz/(xy+yz+xz)xy=x+y,yz=2(y+z),zx=3(z+x),求xyz/(xy+yz+xz) 求证不等式 xyz[yz(y+z)+zx(z+x)+xy(x+y)]>=2(xy+yz+xz)^2 (x^2+yz)/(x^2+x(y-z)-yz)+(y^2-xz)/(y^2+y(x+z)+zx)+(z^2+yx)/(x^2-z(x-y)-yx)最后一项应为：(z^2-xy)/(z^2+z(y-x)-xy) 2yz/x+2xz/y+2xy/z≥2x+2y+2z 若|x-3|+|y+2|+|2z+1|=0,求(xy-yz)(y-x+z) 已知XY=2(X+Y),YZ=4(Y+Z),ZX=5(Z+X),求X,Y,Z已知XY=2(X+Y),YZ=4(Y+Z),ZX=5(Z+X),求X,Y,Z 若Y/X=3/2,Y/Z=3/4.则2XY+YZ/2YZ-XY=多少 若Y/X=3/2,Y/Z=3/4.则(2XY+YZ)/(2YZ-XY)=多少 方程组xy/x+y=2 yz/y+z=4 zx/x+z=5 求x,y,z 求证：(x^3/x+y)+(y^3/y+z)+(z^3/z+x)大于等于（xy+yz+zx)/2 设x,y,z∈R+,xy+yz+xz=1,证明不等式:(xy)^2/z+(xz)^2/y+(yz)^2/x+6xyz≥x+y+zRt 计算,依据图片:{(x^2+yz)÷[x^2+(y-z)x-yz]}+{(y^2+zx)÷[y^2+(z+x)y-zx]}+{(z^2+xy)÷[z^2-(x-y)z-xy]} (x+y-xy)/(x+y+2xy)=(y+z-2yz)/(y+z+3yz)=(z+x-3zx)/(z+x+4zx),且2/x=3/y=1/z,则xyz=? 已知（x+y-xy）/(x+y+2xy)=(y+z-2yz)/(y+z+3yz)=(z+x-3zx)/(z+x+4zx),且2/x=3/y-1/z,则xyz=?