{x+2y+z=10,2x+3y-z=3,3x+2y+2z=17

试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) x/2=y/3=z/5 x+3y-z/x-3y+z 已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 三元一次方程组数学题x+2y+2z=33x+y-2z=72x+3y-2z=10x-y=2z-x=3y+z=-1x-y-z (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai x+2y+3z=10,x-y+4z=10,x+3y+2z=2 2x-y+2z=-17 3x+y-3z=-4 x+y+z=6 x+2y+4z=17 2x+y+z=7 3x+y+2z=11 x-y+4z=10,x+3y+2z=2,x+2y+3z=11. x+y+z=4 2x+3y-z=6 3x+2y+2z=10