{x+y+z=1 {x+3y+7z=2 {x+5y+19z=4
{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=?
{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.
x/2=y/3=z/5 x+3y-z/x-3y+z
2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
2x+5y+4z=0,3x+y-7z=0,则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)
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