2x^2+4xy+2y^2-8z^2

24xy^2z^2(x+y+z)-32xyz(z-x-y)^2+8xyz^3(z-x-y) 24xy^2z^2(x+y+z)-32xyz(z-x-y)^2+8xyz^3(z-x-y) 代数 x^-y^/ x^-(y-z)^ 除以 x^+2xy+y^/(x-y)^-z^ 乘 x^+xy-xz/x^-xy 二元函数Z=x^2-xy+4y^2,求二阶偏导数Zxx Zxy Zyy 化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+（z-y)(x-y)/(xy-2z)(y+z-2x)+(x-z)(y-z)/(y+z-2x)(x-2y+z)速速回答 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] (2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ) 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 若x+y=6,xy=-8,求代数式(x+y-z)^2+(x+y-z)(x+y+z)-2·z(x-y) 若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值 x^2+y^2-2x+4y最小值为z,则（xy）^z= 若x,y,z满足x2+2y2+z2≤2xy-2y+4Z,求x,y,z x^2-4xy+4y^2-9z^2 (xy-1)^2+(x+y-z)(x+y-zxy)因式分解 2x²y·(-4xy³z)计算 12xy(2x+3y+4z)因式分解 x²-y²+5x+3y+4（x+y-2xy)(x+y-z)+(xy-1）²