Tính: \(\left( {\sqrt 8 - 3.\sqrt 2 + \sqrt {10} } \right)\sqrt 2 - \sqrt 5 \)

* Hướng dẫn giải

\(\eqalign{
& \left( {\sqrt 8 - 3.\sqrt 2 + \sqrt {10} } \right)\sqrt 2 - \sqrt 5 \cr & ={\sqrt 8.\sqrt 2 - 3.\sqrt 2.\sqrt 2 + \sqrt {10} }.\sqrt 2 - \sqrt 5 \cr
& = \sqrt {16} - 3.2 + \sqrt {20} - \sqrt 5 \cr  & = \sqrt {4^2} - 6 + \sqrt {2^2.5} - \sqrt 5 \cr
& = 4 - 6 + 2\sqrt 5 - \sqrt 5 = - 2 + \sqrt 5 \cr} \)