Respuesta :

Answer:

1. [tex]4\sqrt{5}[/tex]

2. [tex]10\sqrt{10}[/tex]

Step-by-step explanation:

When you multiply radicals, you do the following

[tex]a\sqrt{b}\cdot c\sqrt{d}\\\\=ac\sqrt{bd}[/tex]

with that in mind

1.

[tex]\sqrt{16}\cdot \sqrt{5}[/tex]

here we don't need to multiply 16 times 5, because 16 = 4^2 and take the square root of it, gives you 4

[tex]=4\sqrt{5}[/tex]

2.

[tex]\sqrt{20}\cdot 5\sqrt{2}\\\\\longrightarrow 20 = 2^2\cdot 5\\\\=2\sqrt{5}\cdot5\sqrt{2}\\\\=(2\cdot5)\sqrt{5\cdot2}\\\\=10\sqrt{10}[/tex]