已知x/2=y/3=z/4,且x+y+z不等于0,求2x+3y-4z/x+y+z的值

已知x/2=y/3=z/4,且x+y+z不等于0,求2x+3y-4z/x+y+z的值 已知4x-3y+z=0,x+2y-8z=0,xyz不等于0,求x+y-z/x-y+2z的值 若x/2=y/3=z/4不等于0,求x+y+z/x+y-z的值 已知x=y/3=z/5.且x+y-2z不等于0.求2x+3y-z/x+y-2z的值是多少 已知x:y:z=2:3:4,且x-y+z=36,求x+y+z的值. 已知x:y:z=2:3:4,且x+y+z=18,求x,y,z的值 已知方程组4x-y+3z=0 2x+y+6z=0且xyz不等于0,则x/y+y/z+z/x是多少 已知x,y,z满足{4x-3y-3z=0,x-3y+z=0.（x不等于0,y不等于0,z不等于0）求x/z和y/z的值 已知x+y/2=y+z/3=z+x/4,且x+2y+z=12,求x-2y+z的值 已知xyz不等于0,且x+2y-z=0,7x-y-z=0,求x+y+z/2x-y-z的值. 方程组｛4x-3y-3z=0,x-3y+z=0,(x.y.z不等于0),求x/z和y/z的值? 4x-3y-3z=0 x-3y+z=0 并且X Y Z不等于0 求x:z 和y:z的值