化简/x/+/-y/-/z/=/ /是绝对值 帮帮忙

(x-2y+z)(x+y-2z)分之（y-x)(z-x) + (x+y-2z)(y+z-2x)分之(z-y)(x-y) + (y+z-2z)(x-2y+z)分之（x-z)(y-z)=?第三部分那个是 （y+z-2x)(x-2y+z)分之（x-z)(y-z) 化简 [x^3(y^2-z^2)+y^3(z^2-x^2)+z^3(x^2-y^2)]/[x^3(y-z)+y^2(z-x)+z^3(x-y)]=是y^3.正确的是化简 [x^3(y^2-z^2)+y^3(z^2-x^2)+z^3(x^2-y^2)]/[x^3(y-z)+y^3(z-x)+z^3(x-y)]= X*(Y+Z)=209,X、Y、Z是质数,求X、Y、Z. X*(Y+Z)=209,X,Y,Z是质数,求X,Y,Z. 已知整数x,y,z满足(x-y)(y-z)(z-x)=x+y+z,证明:x+y+z是27的倍数 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)(y-z)(z-x)=-60 (x+y-z)(x-y+z)= 代数式化简已知z^2=x^2+y^2化简：(x+y+z)(x-y+z)(-x+y+z)(x+y-z) 已知z^2=x^2+y^2,化简(x+y+z)(x-y+z)(-x+y+z)(x+y-z)? 已知x、y是质数,z是奇质数,且x(x+y)=z+8 ,求y(x+z) 化简/x/+/-y/-/z/=/ /是绝对值 帮帮忙 ：设X,Y,Z是正实数,满足XY+Z=(X+Z)(Y+Z),则XYZ的最大值是 微积分...设z=z(x,y)是方程^2+y^2+z^2=y*e^z确定的隐函数,求dz.2x/(y*e^z-2z) dx + 2y/(y*e^z-2z) dy X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 方程组x-y-z=5 y-x-z=1 z-x-y=-15的解是? 已知4X=7Y+5Z,2X+Y=Z,那么X:Y:Z的值是? 已知4X=7y+5z,2x+y=z,那么x:y:z的值是?