1.若{x-3y+3z=0 2x-3y+4z=0,则x:y;z=____
若{x+3y+10z=0 则 (x+y-z)/(x-y+z)
若x-2y+4z=1,x+3y-7z=0,则y:z=?
x-3y+z=0,3x-2y-4z=0,则x:y:z=多少?
已知{x-3y+2z=0 3x-3y-4z+0,则x:y:z=?
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=?::
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
若x/2=y/3=z/4不等于0,求x+y+z/x+y-z的值
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
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