因式分解：-45x^4y^2z^3+18x^3y^2z^2+90x^2y^2z^2

因式分解：25x y^2 z^2 (x+y-z)-30xyz(z-x-y)^2+5x y z^3 (z-x-y) (x+2y-7z)^3+(3x-4y+6z)^3-(4x-2y-z)^3 因式分解 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 因式分解 (x+y+z)^2+yz(y+z)+xyz (y-x)/(x+z-2y)(x+y-2z)+(z-y)(x-y)/(x+y-2z)(y+z-2x)+(x-z)(y-z 因式分解 x^2(y+z)+y^2(z+x)+z^2(x+y)-(x^3+y^3+z^3)-2xyz 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) x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, x/2=y/3=z/5 x+3y-z/x-3y+z 因式分解2(x^2y^2+y^2z^2+z^2x^2)-(x^4+y^4+z^4) 1.（x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2) 化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+（z-y)(x-y)/(x-2z+y)(y+z-2x)+(x