1.
Numerele raționale din A sunt:
[tex]\it -2,3;\ \ -15;\ \ \sqrt{64}=8;\ \ -\dfrac{7}{8}\\ \\ Deci, \ \ A\cap\mathbb{Q}=\Big\{-2,3;\ \ -15;\ \ \sqrt{64};\ \ -\dfrac{7}{8}\Big\}[/tex]
Numerele întregi din A sunt:
[tex]\it -15;\ \ \sqrt{64}=8.\ \ Deci,\ \ A\cap \mathbb{Z}=\{ -15;\ \ \sqrt{64}\}[/tex]
[tex]\it A\setminus \mathbb{Q} =\{\sqrt5;\ \ -2\sqrt3\}\\ \\(elementele\ \ ira\c{\it t}ionale)[/tex]
6.
[tex]\it a)\ \dfrac{^{\sqrt6)}4}{\ 3\sqrt6}=\dfrac{4\sqrt6}{3\cdot6}=\dfrac{4\sqrt6^{(2}}{18}=\dfrac{2\sqrt6}{9}\\ \\ \\ b)\ \dfrac{^{\sqrt3)}9}{\ \sqrt3}=\dfrac{9\sqrt3}{3}=3\sqrt3[/tex]