\(VT=\frac{1}{a^2+b^2+c^2}+\frac{1}{ab+bc+ca}+\frac{1}{ab+bc+ca}+\frac{2016}{ab+bc+ca}\)
\(\ge\frac{9}{\left(a^2+b^2+c^2\right)+\left(ab+bc+ca\right)+\left(ab+bc+ca\right)}+\frac{2016}{\frac{\left(a+b+c\right)^2}{3}}\) \(=\frac{9}{\left(a+b+c\right)^2}+\frac{6048}{\left(a+b+c\right)^2}\ge673\)
Dấu "=" \(\Leftrightarrow a=b=c=1\)