Răspuns:
2. a = 12
3. [tex]\frac{1}{2} [/tex]
Explicație pas cu pas:
2.
[tex]a = \sqrt{5} (\frac{1}{\sqrt{5} } +\sqrt{5} ) + (\sqrt{3} - \frac{1}{\sqrt{3} } )* 3\sqrt{3} [/tex]
[tex]a =( \frac{\sqrt{5} }{\sqrt{5} } + \sqrt{5} *\sqrt{5} ) + 3\sqrt{3} *\sqrt{3} - \frac{3\sqrt{3} }{\sqrt{3} } [/tex]
[tex]a = (1 + 5) + (9-3)[/tex]
a = 6 + 6
a = 12
3.
[tex]\frac{\sqrt{13^{2} - 12^{2} } }{\sqrt{6^{2}+8^{2} } } = \frac{\sqrt{169 - 144} }{\sqrt{26 + 64} } = \frac{\sqrt{25} }{\sqrt{100} } = \frac{5}{10} = \frac{1}{2} [/tex]
