已知5x=3y,4z=7y,求x:y:z

已知5x=3y,4z=7y,求x:y:z 已知2x+5y+4z=6 3x+y-7z=-4求x+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+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值 已知3X=4X,5Y=6Z求X+Y：Y+Z 已知x、y、z满足{3x+7y+z=5 ,求x+y+z的值 {4x+10y+z=3 已知x,y,z满足3x+7y+z=5 4x+10y+z=3 求x+y+z的值 已知4x-3y-6z=0,x+2y-7z=0,求5x+2y-z/2x-3y-10z 已知x:y:z=4:5:7,求:(1)2x+3y+z/5z; (2)x+y/y+z. 1.已知x:y:z=4:5:7,求：（一）2x+3y+z/5z； （二）x+y/y+z 非常急, 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 已知3x+7y+z=315和4x+10y+z=420,求x+y+z 已知X+Y=3,Y+Z=4,Z+X=5,求Z,X,Y的值. 已知{x-5y+2z=0 3x-5y-4z=0,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 已知x/4=y/5=z/6,求x+y+z/3x-2y+z的值.