已知3x=4y,3y=4x,求x：y：z

已知3X=4X,5Y=6Z求X+Y：Y+Z (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:x/y=3,x/z=4,求代数式x+y+z/x-y+z的值 已知5x=3y,4z=7y,求x:y:z 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 已知3x=4y,3y=4x,求x：y：z 已知4x-3y-3z=0 x-3y-z=0 (1)求x:y:z 已知X:Y:Z=3:4:5,求4X+3Y-2Z/X+Y+Z的值 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 已知x/3=y/4=z/2,求x+2y-z/x+y+z=? 已知X+Y=3,Y+Z=4,Z+X=5,求Z,X,Y的值. 已知3x+7y+z=315和4x+10y+z=420,求x+y+z 已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值 已知x/4=y/5=z/6,求x+y+z/3x-2y+z的值. 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+z-y=36求x+y+z的值 已知3x=4y=6z,求分式x+y-z/x-y+z的值急 已知x:y:z=2:3:4,且x+z-y=36.求x+y+z的值