数学2x-y=7 y+z=-5 z-x=-7
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
解方程组2x+y-z=7 x+y+z =1 2x-y-z=5
2x+5y+4z=0,3x+y-7z=0,则x+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+2y+z
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
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
已知4X=7Y+5Z,2X+Y=Z,那么X:Y:Z的值是?
x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
已知x+y-7z=0 x-2y+5z=0(xyz不等于0),求x+2y-z/y-2x+12z