已知x/3=y/4=z/5≠0,求4x+2y-5z/3x+4y-7z的值

已知x/3=y/4=z/6≠0,求x+y-z/x-y+z的值 已知{x-5y+2z=0 3x-5y-4z=0,求x：y:z 已知3X=4X,5Y=6Z求X+Y：Y+Z 已知3x+4y+5z=0,2x+3y-4z=0,求(x+y+z)/(x-y+z) 已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/（除以）x-y+z的值. 已知{3x+4y+5z=0,2x+3y-4z=0,求x+y+z/x-y+z的值. 已知2x+3y-4z=0,3x+4y-5z=0.求x+y+z除以x-y+z, 已知4x-3y-6z=0,x+2y-7z=0,求5x+2y-z/2x-3y-10z 已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值 已知4x-3y-6z=0,x+2y-7z=0,且x,y,z≠0,求2x+3y+6z/x+5y+5z的值. 已知4X-3Y-3Z=0和X-3Y+Z=0 求x:z和y：z的值 z≠0 已知方程组4x-3y-2z=0,x-3y+z=0,z≠0求x/z,y/z的值 (x+y):(y+z):(z+x)=3:4:5 3x+y-z=-4已知(x+y):(y+z):(z+x)=3:4:5 ；3x+y-z=-4求x y z 已知4x-5z=y-x+6z=x+y+z,xyz≠0,求x：y:：z 已知2x+3y-4z=0,3x+3y+5z=0,求x+y+x/x-y+z的值 已知x,y,z满足方程组：4x-5y+2z=o;x+4y-3x=0,求x:y:z的值 已知方程组2x-3y-4z=0和x+y+z=0,并且z≠0,求x：y与y：z 已知x/3=y/4=z/5≠0,求4x+2y-5z/3x+4y-7z的值