[tex]\it B=\{x\in\mathbb{N}\Big |\ 29<x^2<82\} = \{x\in\mathbb{N}\Big |\ 36\leq x^2\leq 81\} = \{6,\ 7,\ 8,\ 9\}[/tex]
[tex]\it D=\{x\in\mathbb{Z}\Big |\ 11<x^2<65\} = \{x\in\mathbb{Z}\Big |\ 16\leq x^2\leq 64\} =\{\pm4,\ \pm5,\ \pm6,\ \pm7,\ \pm8\}}[/tex]
[tex]\it E=\{x\in\mathbb{N} \Big | 20\leq\sqrt x\leq22\} = \{x\in\mathbb{N} \Big | 20^2\leq x \leq22^2\} = \{400,\ 401,\ 402,\ ...\ 484\}[/tex]
