\(\sqrt{1} = 1\)

\(\sqrt{49} = 7\)

\(\sqrt{196} = 14\)

\(\sqrt{9} - \sqrt{81} = 3 - 9 = -6\)

\(4 \sqrt{81} - 7 \sqrt{121} = 4 ⋅ 9 - 7 ⋅ 11 = -41\)

\(\sqrt{9} ⋅ \sqrt{25} = 3 ⋅ 5 = 15\)

\((9 \sqrt{8})^{2} = 9^{2} ⋅ \sqrt{8}^{2} = 81 ⋅ 8 = 648 \text{.}\)

\((9 \sqrt{5} - 8) (9 \sqrt{5} + 8) = (9 \sqrt{5})^{2} - 8^{2} = 81 ⋅ 5 - 64 = 405 - 64 = 341 \text{.}\)

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

\(-7 (\sqrt{3})^{2} = -7 ⋅ 3 = -21 \text{.}\)

\(4 \sqrt{6} + 10 \sqrt{6} = 14 \sqrt{6}\)

\(5 \sqrt{2} ⋅ 2 \sqrt{3} = 10 \sqrt{6}\)

\({\sqrt{6} \over \sqrt{3}} = \sqrt{2}\)

\({8 \sqrt{36} \over 4 \sqrt{6}} = {8 \over 4} ⋅ {\sqrt{36} \over \sqrt{6}} = 2 \sqrt{6}\)

\({8 \sqrt{12} \over 2 \sqrt{3}} = {8 \over 2} ⋅ {\sqrt{12} \over \sqrt{3}} = 4 ⋅ \sqrt{4} = 4 ⋅ 2 = 8\)