[tex]formula \: media \: geometrica \\ Mg = \sqrt{a \times b} [/tex]
[tex]a) \: x = ( \sqrt{6} + \sqrt{5})( \sqrt{8} - \sqrt{7}) \\ x = ( \sqrt{6} + \sqrt{5})(2 \sqrt{2} - \sqrt{7}) \\ x = 2 \sqrt{12} - \sqrt{42} + 2 \sqrt{10} - \sqrt{35} \\ x = 4 \sqrt{3} - \sqrt{42} + 2 \sqrt{10} - \sqrt{35} \\ y =( \sqrt{6} + \sqrt{5})( \sqrt{8} + \sqrt{7}) \\ y = ( \sqrt{6} + \sqrt{5})(2 \sqrt{2} + \sqrt{7}) \\ y = 2 \sqrt{12} + \sqrt{42} + 2 \sqrt{10} + \sqrt{35} \\ y = 4 \sqrt{3} + \sqrt{42} + 2 \sqrt{10} + \sqrt{35} \\ [/tex]
