x+2y-4z=0,3x+y-z=0,则x:y:z=?::
若{x+3y+10z=0 则 (x+y-z)/(x-y+z)
x-3y+z=0,3x-2y-4z=0,则x:y:z=多少?
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
x+2y-4z=0 3x+y-z=0,则x:y:z=
x+2y-4z=0,3x+y-z=0,则x:y:z=?::
已知{x-3y+2z=0 3x-3y-4z+0,则x:y:z=?
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
已知x+2y-4z=0,3x-y-z=0,则3x+2y+z/x+2y+z=
已知方程组4x-y+3z=0 2x+y+6z=0且xyz不等于0,则x/y+y/z+z/x是多少
已知,方程组:4x-3y-7z=0 x+2y=10z 则(x-y+z)÷(x+y+z)=——
2x+3y-4z=0.,3x+4y+5z=0,则x+y+z/x-y+z详细的解题过程
已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3