z不等于0,且4x-7y-5z=0,2x-y-z=0求x/y

已知x,y,z满足方程组x-2y+z=0 7x+4y-5z=0,且z不等于0,2x²-3y²+z²/y²-2z²的值为? z不等于0,且4x-7y-5z=0,2x-y-z=0求x/y 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. 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 若(4x-3y-3z)^2+|x-3y-z|=0 且xyz不等于0 则4x+y-z/x+y+z 的值 已知5分之X+Y=6分之Y+Z=7分之x+z,且X,Y,Z都不等于0,求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xy/5=y+z/6=z+x/7,且xyz不等于0,求x:y:z 已知2X+5Y+4Z=0,3X+Y-7Z=0,且XYZ不等于0,求（X+Y+Z）/(2X-3Y+4Z)的值 已知2X+5Y+4Z=0,3X+Y-7Z=0,且XYZ不等于0,求（X+Y+Z）/(2X-3Y+4Z)的值 已知xyz不等于0,且2x-y+z=0,x-2y+3z=0,求代数式(x²+3y²+5z²)/(2x²+4y²+7z²)的值 已知4x-5y+2z=0,x+4y-3z=0 且xyz不等于0,求x:y:z的值. 若xyz不等于0,且{4x-5y+2z=0,x+4y-3z=0,求x:y:z 若xyz不等于0,且4x-5y+2z=0,x+4y-3z=0,求x：y：z的值. 已知xyz不等于0,且x/3=y/4=z/5,求【2x-3(2y-z)】/x+y+z 已知方程组{X+Y-7Z=0(1)3X-2Y-Z=0(2)且Z不等于0求X:Y:Z 已知xyz不等于0,且{x+3y+5z=0 x2+3y+z=0,则x.x+y.y-2z.2z/3x.3x+2y.2y+z.z=?