Ответ:\(\sqrt{2}\cdot\sqrt{2}=2\).\(\sqrt{3}\cdot\sqrt{3}=3\).\(2\sqrt{3}\cdot\sqrt{3}=2\cdot3=6\).\(4\sqrt{5}\cdot\sqrt{5}=4\cdot5=20\).\(3\sqrt{2}\cdot2\sqrt{2}=3\cdot2\cdot2=12\).\(5\sqrt{7}\cdot3\sqrt{7}=5\cdot3\cdot7=105\).