10 . 40 = 10 . 40 = 400 = 20

5 . 45 = 5 . 45 = 225 = 15

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

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

a,= \(\sqrt{1296}\)=36

b,=\(\sqrt{4}\) =2