(1) -16x^2 y^2+12x^3 y^5 z - 8xy^2 z^3 (2) x^3-6x^2+9x (3) (
(1) -16x^2 y^2+12x^3 y^5 z - 8xy^2 z^3 (2) x^3-6x^2+9x (3) (
1.(x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2)
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
x/2=y/3=z/5 x+3y-z/x-3y+z
实数x、y、z满足x=6-3yx+3y-2xy+2z
1.x+y=16,y+z=12,z+x=102.3x-y+z=4,2x+3y-z=12,x+y+z=63.x+y+z=6
若x/3=y/2=z/5,且xy+yz+zx=93,求9x*x+12y*y+2z*z的值.
解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y
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+y+z=1;x+3y+7z=-1;z+5y+8z=-2
xy/x+y=1,yz/y+z=2,xz/x+z=3求x,y