Matrix Transformations of Vectors Practice Test

For the transformation $T(\mathbf{v})=A\mathbf{v}$ with $$A=\begin{pmatrix}-1 & 0 \\ 0 & 1\end{pmatrix},$$ where does the point $$\mathbf{v}=\begin{pmatrix}4 \-2\end{pmatrix}$$ map to? (Compute $A\mathbf{v}$.)

Given the matrix

$$A=\begin{pmatrix}2 & 1\-3 & 0\end{pmatrix}$$

and a general column vector

$$\mathbf{v}=\begin{pmatrix}x\y\end{pmatrix},$$

what is the general form of $A\mathbf{v}$?