Let $\left|\overrightarrow{A_1}\right|=3,\left|\overrightarrow{A_2}\right|=5$ and $\left|\overrightarrow{A_1}+\overrightarrow{A_2}\right|=5$. The value of $\left(2 \overrightarrow{A_1}+3 \overrightarrow{A_2}\right) \cdot\left(3 \overrightarrow{A_1}-2 \overrightarrow{A_2}\right)$ is:
