\(\sqrt{1}=1\)

\(\sqrt{25}=5\)

\(\sqrt{81}=9\)

\(\sqrt{81}-\sqrt{49}=9-7=2\)

\(8\sqrt{49}+4\sqrt{81}=8⋅7+4⋅9=92\)

\(\sqrt{81}⋅\sqrt{49}=9⋅7=63\)

\((3\sqrt{2})^2=3^2⋅\sqrt{2}^2=9⋅2=18\text{.}\)

\((5\sqrt{8}+2)(5\sqrt{8}-2)=(5\sqrt{8})^2-2^2=25⋅8-4=200-4=196\text{.}\)

\((\sqrt{6})^2=6\text{.}\)

\(2(\sqrt{5})^2=2⋅5=10\text{.}\)

\(3\sqrt{7}+4\sqrt{7}=7\sqrt{7}\)

\(6\sqrt{17}⋅3\sqrt{3}=18\sqrt{51}\)

\({\sqrt{35} \over \sqrt{5}}=\sqrt{7}\)

\({30\sqrt{30} \over 5\sqrt{6}}={30 \over 5}⋅{\sqrt{30} \over \sqrt{6}}=6\sqrt{5}\)

\({63\sqrt{32} \over 9\sqrt{8}}={63 \over 9}⋅{\sqrt{32} \over \sqrt{8}}=7⋅\sqrt{4}=7⋅2=14\)