x+y+z=1 4x+5y-z=6 x+2y-z=3

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. x/2=y/3=z/5 x+3y-z/x-3y+z 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? {2x+3y-4z=-5 x+y+z=6 x-y+3z=10 解方程组：x+y+z=4,x+y+2z=5,3x+y-z=6 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 5x+3y+2z=2011 4x+6y+7z=2012 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. 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?