Let $A$ be a non – singular matrix such that $A^{-1}=\left(\begin{array}{ccc}1& 1& 1\\ 4& 6& 8\\ 100& 100& 99\end{array}\right)$  then the value of  $\det \left(\mathrm{Adj}\left(2\mathrm{A}\right)\right)+\det \left(2\mathrm{A}\right)$ is 

$$\begin{gathered} \left|A^{-1}\right|=\left|\begin{array}{ccc}1& 1& 1\\ 4& 6& 8\\ 100& 100& 99\end{array}\right|=\left|\begin{array}{ccc}0& 0& 1\\ -2& -2& 8\\ 0& 1& 99\end{array}\right|=-2 \\ \therefore \left|A\right|=\frac{1}{-2} \\ \left|Adj\left(2A\right)\right|+\left|2A\right|={\left|2A\right|}^2+2^3\left|A\right| \\ ={\left(2^3\left|A\right|\right)}^2+2^3\left|A\right| \\ =2^6.\frac{1}{4}+2^3\left(\frac{-1}{2}\right) \\ =16-4=12 \end{gathered}$$