3x-y+z=4 2x+3y-2z=12

x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 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 解方程组{3x+y-z=4,2x-y+3z=12,x+y+z=6} 解方程{3x -y+z=4 2x+3y-z=12 x+y+z=6 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 已知x+y/2=y+z/3=z+x/4,且x+2y+z=12,求x-2y+z的值 ①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z- 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 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai 如果x+4/3=y+z/2=z+8/4,且x+y+z=12,求x,y,z的值.