16.(2022秋•成都期末)已知实数xxx,yyy满足2x2+4xy+5y2=12x^{2}+4xy+5y^{2}=12x2+4xy+5y2=1,则x2+y2x^{2}+y^{2}x2+y2的最小值为 ___16\frac{1}{6}61___.