7.
$$\mathbf { A } ( x ) = \left( \begin{array} { c c c }
1 & x & - 1
3 & 0 & 2
1 & 1 & 0
\end{array} \right) , x \neq \frac { 5 } { 2 }$$
- Calculate the inverse of \(\mathbf { A } ( x )\).
$$\mathbf { B } = \left( \begin{array} { c c c }
1 & 3 & - 1
3 & 0 & 2
1 & 1 & 0
\end{array} \right)$$
The image of the vector \(\left( \begin{array} { c } p
q
r \end{array} \right)\) when transformed by \(\mathbf { B }\) is \(\left( \begin{array} { l } 2
3
4 \end{array} \right)\) - Find the values of \(p , q\) and \(r\).