Let
\[
A=
\begin{bmatrix}
1 & 3 & -1\\
2 & 1 & \alpha\\
0 & 1 & -1
\end{bmatrix}
\]
be a singular matrix. Let
\[
f(x)=\int_{0}^{x}(t^2+2t+3)\,dt,\quad x\in[1,\alpha].
\]
If \(M\) and \(m\) are respectively the maximum and the minimum values of \(f\) in \([1,\alpha]\), then \(3(M-m)\) is equal to :