# How do you find the inverse of A=((0, 7), (0, -3))?

$\left\mid \begin{matrix}0 & 7 \\ 0 & - 3\end{matrix} \right\mid = \left(0 \cdot - 3\right) - \left(7 \cdot 0\right) = 0$ so $A$ has no inverse.