math

1. 21-22
21-22

2. 60
2 5
60 10
24
60 60
5h 25' 30"
5 25 30 60
5 25/60 30/3600 5
4/10 2/100 5/1000
. 1854
82 = 1 4
82 = 1 4 = 1 x 60 + 4 = 64
592 = 58 1 (=58 x 60 + 1 = 3481)

3. a b
a.b = ((a+b)2-
a2-b2)/2
-
->
a.b = (a+b)2/4 -
(a-b)2/4
5.3 (64/4) - 4/4 = 15
a/b = a.(1/b)
b
2 30
3 20

4. 4 15
5 12
6 10
8 7 30
9 6 40
10 6
12 5
15 4
16 3 45
18 3 0
20 3
24 2 30
25 2 24
27 2 13 20
2/3 = 2.(1/3) = 2.(20/60) =
40/60
40 1
60
60

5. 1/13 7/91 7/90
,