x^2-xy+2yz-4z^2

(2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ) x^2-xy+2yz-4z^2因式分解 x^2-xy+2yz-4z^2 x的平方-xy+2yz-4z的平方 化简x²-xy+2yz-4z² 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) 求(2X+Z-Y)/(X^2-XY+XZ-YZ)-(2X+Y+Z)/(X^2+XY+XZ+YZ) 因式分解x^2yz-xy^2z+xyz^2 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) 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] 求证不等式 xyz[yz(y+z)+zx(z+x)+xy(x+y)]>=2(xy+yz+xz)^2 xy 2yz 3zx 4xyz________ = ________ = _______ = ___________ (xyz不等于0)x+y+xy y+z+yz z+x+zx xy+yz+zx最好有解题思路 算出 X Y Z 分别等于几 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 方程组xy/x+y=2 yz/y+z=4 zx/x+z=5 求x,y,z x^2+y^2+xy=25/4,x^2+z^2+xz=169/4,y^2+z^2+yz=36,求xy+xz+yz XYZ满足XY/X+Y=-2,YZ/Y+Z=3/4,ZX/Z+X=-4/3,求XYZ/XY+YZ+ZX的值 数学题 xy&x+y =-2,yz&y+z=4&3 zx&z+x=-4&3 求XYZ%xy+xz+yz x+y分之xy=5,y+z分之yz=2分之7,z+x分之zx=4,则xy+yz+zx分之xyz=?