Answer:
[tex]3 \sqrt{2} \times \sqrt{10} \\ 3 \sqrt{20 } \\ 3 \sqrt{4 \times 5} \\ 3 \times 2 \sqrt{5} \\ 6 \sqrt{5} [/tex]
the answer is a
[tex]3\sqrt{2} \cdot\sqrt{10} =3\sqrt{2\cdot10} =3\sqrt{20} =3\sqrt{2^2\cdot5} =3\cdot2\sqrt{5} =\boxed{6\sqrt{5} }[/tex]
