已知(x+1)^2+3(y-2)^2+|y-z-5|=0,则x=?,y=?,z=?
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
已知x-y+z=0,3x+y-5z=0,则x+y+z/x+2y-3z=?
已知x-y+z=0.3x+y-5z=0,则x+y+z/x+2y-3z=_______
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-3y+2z=0 3x-3y-4z+0,则x:y:z=?
已知2x+5y+4z=15.7x+y+3z=14 则x+y+z=?
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z均不为0,求3x*x+2y*y+5z*z/5x*x+y*y-
已知 x,y,z都是正实数,且 x+y+z=xyz 证明 (y+x)/z+(y+z)/x+(z+x)/y≥2(1/x+1
已知x+2y-4z=0,3x-y-z=0,则3x+2y+z/x+2y+z=
已知x+y-z=0,2x-y+2z=0 求(3x-2y+5z)/(5x-3y+2z)的值
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
已知x+2y-3z=0,2x+3y+5z=0,求(x+y+z)除以(x-y+z)