x-2y+4z=0 x+3y-7z=1 则2x+y-3z的值为?

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 六年级三元一次方程组.解下列方程组：(1)5x-3y+z=25x+2y-4z=3-5x+y-z=2(2)x-y-z=-13x_5y+7z=114x-y+2z=-1(3)9x-5y+z=-69x+y+4z=3-9x+3y-5z=0(4)x+y=22x+z=-27y+z=13 (1)X+Y=15,Y+Z=-6,Z+X=7.(2)X+Y=-14,Y+Z=-7,Z+X=9.(3)X+Y=0,Y+Z=-1,Z+X=-1. 2x+z=10 x+y-z=4 3x-y-z=0 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 X-Y-Z=0 X+Y-3Z=4 2X-5Y+7Z=21 3X+Y+Z=0,2X-Y+3Z=1,X+2Y-Z=4 {x+y+z=1 {x+3y+7z=2 {x+5y+19z=4 若4x-3y-6z=0,x+2y-7z=0,则x+y+z/3x-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=? 解三元一次方程组 ①2x-y+z=1 3x+y -2z=2 X+2y-z=3 ②x-4y+z=-3 2x+Y-Z=18 X-Y-Z=7 ③4x+4y+2z=7 6X-4y-z=6 2x-y+z=1 已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值 已知4x-3y-6z=0,x+2y-7z=0,则x-y+z/x+y+z=_________ 已知4x-3y+6z=0 x+2y-7z=0 则x-y+z/x+y-z=? 4x-3y-6z=0,x+2y-7z=0,x-y+z/x+y+z=? 已知{4x-3y-6z=0、x+2y-7z=0,则x-y+z：x+y+z=