x+y+z=2,xyz=1,x2+y2+z2=6x+y+z=2,xyz=1,x^2+y^2+z^2=6x+y+z=2,xyz=1,x2+y2+z2=6 ,求 12x+xy+12x+yz+12x+2y\frac{1}{2x+xy}+\frac{1}{2x+yz}+\frac{1}{2x+2y}2x+xy1+2x+yz1+2x+2y1 的值,bdfs无果。