Answer
3 and 0
Work Step by Step
The singular values of the matrix are the square roots of the eigenvalues of $A^TA$.
$A^TA=\begin{bmatrix}
-3&0\\0&0
\end{bmatrix}\begin{bmatrix}
-3&0\\0&0
\end{bmatrix}=\begin{bmatrix}
9&0\\0&0
\end{bmatrix}$. The eigenvalues are 9 and 0, so the singular values are 3 and 0.