Row 1, column 1:
Hint: Row 1 of $A$ is $\begin{pmatrix} -3 & 6 \end{pmatrix}$. Column 1 of $B$ is $\begin{pmatrix} 11 \\ 12 \end{pmatrix}$. Multiply in pairs and add the results.
Row 1, column 2:
Hint: Row 1 of $A$ is $\begin{pmatrix} -3 & 6 \end{pmatrix}$. Column 2 of $B$ is $\begin{pmatrix} 9 \\ 7 \end{pmatrix}$. Multiply in pairs and add the results.
Row 2, column 1:
Hint: Row 2 of $A$ is $\begin{pmatrix} 2 & 12 \end{pmatrix}$. Column 1 of $B$ is $\begin{pmatrix} 11 \\ 12 \end{pmatrix}$. Multiply in pairs and add the results.
Row 2, column 2:
Hint: Row 2 of $A$ is $\begin{pmatrix} 2 & 12 \end{pmatrix}$. Column 2 of $B$ is $\begin{pmatrix} 9 \\ 7 \end{pmatrix}$. Multiply in pairs and add the results.