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