Row 1, column 1:
Hint: Row 1 of $A$ is $\begin{pmatrix} 6 & 0 \end{pmatrix}$. Column 1 of $B$ is $\begin{pmatrix} 4 \\ 1 \end{pmatrix}$. Multiply in pairs and add the results.
Row 1, column 2:
Hint: Row 1 of $A$ is $\begin{pmatrix} 6 & 0 \end{pmatrix}$. Column 2 of $B$ is $\begin{pmatrix} -2 \\ 8 \end{pmatrix}$. Multiply in pairs and add the results.
Row 2, column 1:
Hint: Row 2 of $A$ is $\begin{pmatrix} 4 & -6 \end{pmatrix}$. Column 1 of $B$ is $\begin{pmatrix} 4 \\ 1 \end{pmatrix}$. Multiply in pairs and add the results.
Row 2, column 2:
Hint: Row 2 of $A$ is $\begin{pmatrix} 4 & -6 \end{pmatrix}$. Column 2 of $B$ is $\begin{pmatrix} -2 \\ 8 \end{pmatrix}$. Multiply in pairs and add the results.
Row 3, column 1:
Hint: Row 3 of $A$ is $\begin{pmatrix} -1 & 2 \end{pmatrix}$. Column 1 of $B$ is $\begin{pmatrix} 4 \\ 1 \end{pmatrix}$. Multiply in pairs and add the results.
Row 3, column 2:
Hint: Row 3 of $A$ is $\begin{pmatrix} -1 & 2 \end{pmatrix}$. Column 2 of $B$ is $\begin{pmatrix} -2 \\ 8 \end{pmatrix}$. Multiply in pairs and add the results.