Use the formula of a distance between two points:
[tex]d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]
[tex](-8,\ -6),\ (4,\ 10)\\\\d=\sqrt{(4-(-8))^2+(10-(-6))^2}=\sqrt{12^2+16^2}\\\\=\sqrt{144+256}=\sqrt{400}=\boxed{20}\\\\(5,\ 14),\ (-3,\ -9)\\\\d=\sqrt{(-3-5)^2+(-9-14)^2}=\sqrt{(-8)^2+(-23)^2}\\\\=\sqrt{64+529}=\boxed{\sqrt{593}\approx24.35}[/tex]