Respuesta :

We have that

[tex]\begin{gathered} 3\cdot\sqrt[]{45}=3\cdot(\sqrt[]{9\cdot5}) \\ =\text{ 3(}\sqrt[]{9}\cdot\sqrt[]{5}\text{)} \\ =\text{ 3(3 }\cdot\sqrt[]{5}) \\ =9\cdot\sqrt[]{5} \end{gathered}[/tex]

So the answer is

[tex]9\cdot\sqrt[]{5}[/tex]