5x+4y+z=-7 4x+y-4z=-13 x+y+z=0
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
若4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10
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=?
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
已知2x+5y+4z=6.3x+y-7z=-4 求 x+2y+z
3x+7y+z=5 ,4x+10y+z=6 ,x+y+z=
若3x+7y+z=5,4x+10y+z=3,则x+y+z=?
x*x+y*y+2z*z-2x+4y+4z+7=0,求xyz的值
5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
若4x=7y+5z,2x+y=z,则x:y:z的值为