[tex]\displaystyle\bf\\3)\\\\\sqrt{25} < \sqrt{26} < \sqrt{36} \\\\5 < \sqrt{26} < 6\\\\\\\sqrt{100} < \sqrt{110} < \sqrt{121} \\\\10 < \sqrt{110} < 11\\\\\\\sqrt{4} < \sqrt{6,25} < \sqrt{9} \\\\2 < \sqrt{6,25} < 3\\\\\\-\sqrt{16} < -\sqrt{11} < -\sqrt{9} \\\\-4 < -\sqrt{11} < -3\\\\\\-\sqrt{1} < -\sqrt{0,5} < 0\\\\-1 < -\sqrt{0,5} < 0[/tex]

[tex]\displaystyle\bf\\4)\\\\7 \ \ i \ \ \sqrt{70} \\\\\sqrt{49} \ \ ; \ \ \sqrt{64} \ \ ; \ \ \sqrt{70} \\\\7 \ \ ; \ \ \boxed{ 8} \ \ ; \ \ \sqrt{70} \\\\\\-4 \ \ i \ \ -\sqrt{5} \\\\-\sqrt{16} \ \ ; \ \ -\sqrt{9} \ \ ; \ \ -\sqrt{5} \\\\-4 \ \ ; \ \ \boxed{-3} \ \ -\sqrt{5} \\\\\\-\sqrt{2,9} \ \ i \ \ 0\\\\-\sqrt{2,9} \ \ ; \ \ -\sqrt{1} \ \ ; \ \ 0\\\\-\sqrt{2,9} \ \ ; \ \ \boxed{-1} \ \ ; \ \ 0\\\\\\-\sqrt{20} \ \ i \ \ \sqrt{2,5}[/tex]

[tex]\displaystyle\bf\\-\sqrt{20} \ \ ; \ \ -\sqrt{16} \ \ ; \ \ -\sqrt{9} \ \ ; \ \ -\sqrt{4} \ \ ; \ \ -\sqrt{1} \ \ ; \ \ 0 \ \ ; \ \ 1 \ \ ; \ \ \sqrt{2,5} \\\\-\sqrt{20} \ \ ; \ \ \boxed{-4} \ \ ; \ \ \boxed{-3} \ \ ; \ \ \boxed{-2} \ \ ; \ \ \boxed{-1} \ \ ; \ \ \boxed{0} \ \ ; \ \ \boxed{1} \ \ ; \ \ \sqrt{2,5}[/tex]