如果x/2=y/7=z/5,xyz不等于0,求x+y+z/3x-y的值

如果x/2=y/7=z/5,xyz不等于0,求x+y+z/3x-y的值 已知x+y-7z=0 x-2y+5z=0(xyz不等于0）,求x+2y-z/y-2x+12z 如果x/2=y/3=z/5,且xyz不等于0,则(x+y+z)/（3x-y）, 已知xy/5=y+z/6=z+x/7,且xyz不等于0,求x:y:z 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. (x+y)/3=(y+z)/5=(z+x)/4 ,xyz不等于0,求x:y:z 已知xyz满足|3x-2y+z|+|2x+y+2z|=0（xyz不等于o）求x+y除以z 已知5分之x+y=6分之Y+Z=7分之Z+X,且XYZ不等于0,求X:Y:Z 已知5分之X+Y=6分之Y+Z=7分之Z+X,且XYZ不等于0,求X:Y:Z 已知X+4Y-3Z=0,4X-5Y+2Z=0(XYZ不等于0) 则X:Y:Z=_____ 已知x+4y-3z=0,4x-5y+2z=0(xyz不等于0),则x:y:z=? 已知X+2Y-9Z=0,X-2Y-5Z=0,XYZ不等于0 问：x；y；z 请给我帮助, 已知xyz不等于0,且x/3=y/4=z/5,求【2x-3(2y-z)】/x+y+z 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(1)：x+2y-9z=0,(2)：x-2y-5z=0,xyz不等于0求(2x^2+3y^2+7z^2)/(x^2-4y^2+9z^2)的值. 已知4x-3y-6z=0,x+2y-7z=0(xyz不等于0),求2x+3y+6z除以x+5y+7z的值