Matrices And Determinants

Let \(\mathrm{A}\) be a \(2 \times 2\) matrix with real entries such that \(\mathrm{A}'=\alpha \mathrm{A}+\mathrm{I}\), where \(\alpha \in \mathbb{R}-\{-1,1\}\). If \(\operatorname{det}\left(A^{2}-A\right)=4\), then the sum of all possible values of \(\alpha\) is equal to :