Find $\mathrm{M}_{12}$. \[ A=\left[\begin{array}{rrr} 5 & 5 & 7 \\ 3 & 3 & -2 \\ 0 & 1 & 5 \end{array}\right] \]

Step 1 ：Given matrix A is \[A=\left[\begin{array}{rrr} 5 & 5 & 7 \ 3 & 3 & -2 \ 0 & 1 & 5 \end{array}\right]\]

Step 2 ：The element in the first row and second column of matrix A is denoted as \(M_{12}\)

Step 3 ：So, \(M_{12} = 5\)

Step 4 ：Final Answer: \(\boxed{5}\)