7.
$$\mathbf { P } = \left( \begin{array} { c c }
3 a & - 2 a
- b & 2 b
\end{array} \right) , \quad \mathbf { M } = \left( \begin{array} { c c }
- 6 a & 7 a
2 b & - b
\end{array} \right)$$
where \(a\) and \(b\) are non-zero constants.
- Find \(\mathbf { P } ^ { - 1 }\), leaving your answer in terms of \(a\) and \(b\).
Given that
$$\mathbf { M } = \mathbf { P Q }$$
- find the matrix \(\mathbf { Q }\), giving your answer in its simplest form.
\includegraphics[max width=\textwidth, alt={}, center]{9093bb1d-4f32-44e7-b0e7-b8c4f8a844e1-19_95_77_2617_1804}