Answer:
[tex]\large\boxed{2\sqrt{10}\cdot3\sqrt{12}=12\sqrt{30}}[/tex]
Step-by-step explanation:
[tex]2\sqrt{10}\cdot3\sqrt{12}=(2\cdot3)\sqrt{10\cdot12}=6\sqrt{120}=6\sqrt{4\cdot30}=6\cdot\sqrt4\cdot\sqrt{30}\\\\=6\cdot2\cdot\sqrt{30}=12\sqrt{30}\\\\\text{used}\ \sqrt{ab}=\sqrt{a}\cdot\sqrt{b}[/tex]