\(\sqrt{80}+\sqrt{500}=\sqrt{16}⋅\sqrt{5}+\sqrt{100}⋅\sqrt{5}=4\sqrt{5}+10\sqrt{5}\text{.}\)

\(4\sqrt{5}+10\sqrt{5}=14\sqrt{5}\text{.}\)

\(\sqrt{20}=\sqrt{4}⋅\sqrt{5}=2\sqrt{5}\text{.}\)

\(7\sqrt{28}=7⋅\sqrt{4}⋅\sqrt{7}=7⋅2⋅\sqrt{7}=14\sqrt{7}\text{.}\)

\(2\sqrt{200}-3\sqrt{32}=2⋅\sqrt{100}⋅\sqrt{2}-3⋅\sqrt{16}⋅\sqrt{2}\text{.}\)

\(2⋅10⋅\sqrt{2}-3⋅4⋅\sqrt{2}=20\sqrt{2}-12\sqrt{2}=8\sqrt{2}\text{.}\)

\(\sqrt{\frac{1}{25}}={\sqrt{1} \over \sqrt{25}}=\frac{1}{5}\text{.}\)