$$
(2 \sqrt{12}-4 \sqrt{27}+3 \sqrt{75}+7 \sqrt{8}-3 \sqrt{18}) \cdot(4 \sqrt{48}-3 \sqrt{27}-5 \sqrt{18}+2 \sqrt{50})=?
$$
The given expression can be written as:

$$
\begin{gathered}
(4 \sqrt{3}-12 \sqrt{3}+15 \sqrt{3}+14 \sqrt{2}-9 \sqrt{2}) \cdot(16 \sqrt{3}-9 \sqrt{3}-15 \sqrt{2}+10 \sqrt{2})= \\
=(7 \sqrt{3}+5 \sqrt{2})(7 \sqrt{3}-5 \sqrt{2})=(7 \sqrt{3})^{2}-(5 \sqrt{2})^{2}=97
\end{gathered}
$$

(Balázs Tóth, Eger.)

Number of solutions: 41.