x+2y=3x+2z=4y+z 求x:y:z

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) 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 已知x/3=y/4=z/2,求x+2y-z/x+y+z=? 已知x:y:z=3:4:5,3x+2y-4z=18.求：x+y+z. 已知2x=3y=4z求2x-y+z分之x+y+z的值 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z x/3=y/4=z/5,求x+y+z/3x-2y+z的值, 若x/3=y/4=z/5,求x+y+z/3x-2y+z的值. 若x:y:z=2:3:4,求x+y+z/x-2y+3z的值 x：y：z=2：3：4 求 3x+2y-z/x+y+z 的值 5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z