2x+3y-4z=7,x+3y-5z=2,则x+2y-3z的值为（）2x+3y-4z=7,x+3y-5z=2,则x+2y-3z的值为

2x+5y+4z=6,3x+y-7z=-4,x+y-z=? X-Y-Z=0 X+Y-3Z=4 2X-5Y+7Z=21 3x+7y+4z=35,x+5y+2z=40,x+y+z=( ) {x+y+z=1 {x+3y+7z=2 {x+5y+19z=4 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 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 1.{x:y:z=3:4:5 2x+3y-5z=-142.{x-y-z=-1 3x+5y+7z=11 4x-y+2z=-13.{x+y=1 x+z=0 2x+y+2z=44.{x-y+z=-3 2x-y-z=-2 -3x+y+z=-15.{x-y+z=-3 3x+y-4z=6 2x+y-z=36.{x-2y+5z=16 2x+y-5z=7 2x-y+z=38 已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值 已知关于x y z的方程组2x-3y+5z=7 x+2y-3z=8,则4x+y-z= 已知4x-3y-6z=0,x+2y-7z=0,求5x+2y-z/2x-3y-10z x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=? 三元一次方程 X-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 X=?Y=?Z=? x/2=y/3=z/5 x+3y-z/x-3y+z x+2y=3x+2z=4y+z 求x:y:z x+y/2=z+x/3=y+z/4 x+y+z=27 {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 三元一次方程组2x+z=3 3x+y-z=8 x+3y+2z=3 5x+2y-3z=2 x+2y+z=6 7x-2y-4z=262x+z=3 3x+y-z=8 x+3y+2z=3 5x+2y-3z=2 x+2y+z=6 7x-2y-4z=26