已知x/3=y/4=z/5≠0,求2x-y/x+2y-3z的值.此题为八年级下学期有关分式的问题

已知{x-5y+2z=0 3x-5y-4z=0,求x：y:z 已知4x-3y-6z=0,x+2y-7z=0,求5x+2y-z/2x-3y-10z 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x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z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,且x,y,z≠0,求2x+3y+6z/x+5y+5z的值. 已知方程组4x-3y-2z=0,x-3y+z=0,z≠0求x/z,y/z的值 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/2 = y/3 = z/5 ≠ 0 求 (x-y+3z) / (3x+2y) 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2x+5y+4z=6 3x+y-7z=-4求x+y-z 已知X:Y:Z=3:4:5,求4X+3Y-2Z/X+Y+Z的值 已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值