x/3=y/4=z/5,求x+y+z/3x-2y+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 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z x+2y=3x+2z=4y+z 求x:y:z 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 已知3X=4X,5Y=6Z求X+Y：Y+Z x,y,z不是0.3z=4y,z=3x求（x+y）：（x+z）. 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 一只x/3=y/4=z/5,求x+y+z/x及x+y+z/x-y+z的值 2x+Y+3z=23,x+4y+5z=36,求X+2Y+3z~ 若x/3=y/4=z/5,求x+y+z/3x-2y+z的值. x/3=y/4=z/5,求x+y+z/3x-2y+z的值, 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2x+5y+4z=6 3x+y-7z=-4求x+y-z 已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值 若x:y:z=3:4:5=6,求x-y+z分之x+y-z的值 已知x/4=y/5=z/6,求x+y+z/3x-2y+z的值.