3／x=4／y=5／z,求2x/x+y+2的值快牙

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(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 3x=4y 2y=5z 试求x:y:z 已知x:：y：z=3：4：5,(1)求x+y分之z的值；（2）若x+y+z=6,求x,y,z. 2x+Y+3z=23,x+4y+5z=36,求X+2Y+3z~ 已知{x-5y+2z=0 3x-5y-4z=0,求x：y:z 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 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: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. 5x+3y+2z=2011 4x+6y+7z=2012 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 方程组{x/2+y/3-z=-5,x/3-y/2+z/2=10,x/2-y/3-z/4=6,求x,y,z x+y-2z=5 2x-y-z=4 3x+y-3z=10；分别求x、y、z的值.