Mathematics - Matrix Question with Solution | TestHub

If$B=\left[\begin{array}{ccc}5& 2\alpha & 1\\ 0& 2& 1\\ \alpha & 3& -1\end{array}\right]$is the inverse of a$3\times 3$matix$A,$then the sum of all values of$\alpha$for which$det\left(A\right)+1=0,$is: