Thực hiện phép tính: a) \(\sqrt {25.144} \); b) \(\sqrt {52.13} \); c) \(\sqrt 2 \left( {4\sqrt 2 - 6} \right) + \sqrt {72} \).

a) \(\sqrt {25.144} = \sqrt {25} .\sqrt {144} = 5.12 = 60\).

b) \(\sqrt {52.13} = \sqrt {4.13.13} = \sqrt {{{4.13}^2}} = \sqrt 4 .\sqrt {{{13}^2}} = 2.13 = 26\).

c) \(\sqrt 2 \left( {4\sqrt 2 - 6} \right) + \sqrt {72} = 4\sqrt 2 .\sqrt 2 - 6\sqrt 2 + \sqrt {36.2} = 8 - 6\sqrt 2 + 6\sqrt 2 = 8\).