x+2y+3z=6(1) 3x-y-z=1(2) 4x+5y-7z=2(3)

{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出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. 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 {5x-3y+z=2{5x+2y-4z=3{-5x+y-z=2 {x-y-z=-1{3x+5y+7z{4x-y+2x=- 已知x:y:z=4:5:7,求:(1)2x+3y+z/5z; (2)x+y/y+z. 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? 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 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) x/2=y/3=z/5 x+3y-z/x-3y+z （1）{x-y=2 z-x=3 y+z=-1 （2）{x-y-z=2 3x+5y+7z=24 4x-y+2z=26