5 . 45 = 5 . 45 = 225 = 15

a) = \(\sqrt{10.40}=\sqrt{400}=\sqrt{20^2}=20\)

b) \(=\sqrt{5.45}=\sqrt{5^2.3^2}=\sqrt{15^2}=15\)

10 . 40 = 10 . 40 = 400 = 20

52 . 13 = 4 . 13 . 13 = 2 . 13 2 = 2 . 13 = 26

2 . 162 = 2 . 2 . 81 = 2 . 9 2 = 2 . 9 = 18