\(\sqrt{0}=0\)

\(\sqrt{49}=7\)

\(\sqrt{121}=11\)

\(\sqrt{81}-\sqrt{4}=9-2=7\)

\(5\sqrt{64}-9\sqrt{144}=5⋅8-9⋅12=-68\)

\(\sqrt{25}⋅\sqrt{49}=5⋅7=35\)

\((-9\sqrt{6})^2=(-9)^2⋅\sqrt{6}^2=81⋅6=486\text{.}\)

\((9\sqrt{4}-3)(9\sqrt{4}+3)=(9\sqrt{4})^2-3^2=81⋅4-9=324-9=315\text{.}\)

\((\sqrt{5})^2=5\text{.}\)

\(7(\sqrt{10})^2=7⋅10=70\text{.}\)

\(\sqrt{3}-4\sqrt{3}=-3\sqrt{3}\)

\(5\sqrt{3}⋅4\sqrt{2}=20\sqrt{6}\)

\({\sqrt{48} \over \sqrt{8}}=\sqrt{6}\)

\({24\sqrt{36} \over 8\sqrt{6}}={24 \over 8}⋅{\sqrt{36} \over \sqrt{6}}=3\sqrt{6}\)

\({30\sqrt{90} \over 6\sqrt{10}}={30 \over 6}⋅{\sqrt{90} \over \sqrt{10}}=5⋅\sqrt{9}=5⋅3=15\)