[tex] \sqrt{13 + \sqrt{7 + \sqrt{2 + \sqrt{4} } } } = \\ \\ \sqrt{13 + \sqrt{7 + \sqrt{2 + 2 } } } = \\ \\ \sqrt{13 + \sqrt{7 + \sqrt{4} } } = \\ \\ \sqrt{13 + \sqrt{7 + 2} } = \\ \\ \sqrt{13 + \sqrt{9} } = \\ \\ \sqrt{13 + 3} = \\ \\ \sqrt{16} = \\ \\ 4[/tex]
