compare :

35 < .......... < 37

answer :

35 < 36 < 37

75 + 20 + 45 + 55 + 80

=75 + ( 20 + 80 ) + ( 45 + 55 )

= 75 + 100 + 100

= 175 + 100

= 275

34 + 23

= 23 + 34

= 57

63 + 16 + 37 + 50 + 50

= ( 63 + 37 ) + 16 +  ( 50 + 50 )

= 100 + 16 + 100

= 116 + 100

= 216

75 + 29 + 25 + 30 + 71

= ( 75 + 25 ) + ( 29 + 71 ) + 30

= 100 + 100 + 30

= 200 + 30

= 230

1 + 2 = 3

2 + 3 = 5

3 + 4 = 7

4 + 5 = 9

This question is very easy.

=75 + 15 + 25 + 85 + 60 + 50 + 40 + 50 + 10

= 75 + 15 + 25 + 85 + 60 + 40 + 50 + 50 + 10

= 100 + 100 + 100 + 10

= 400 + 10

= 410

x + 2/5 = 1/2

x = 1/2 + 2/5

x = 9/10

x = 0,9

x - 2/5  = 2/7

x = 2/7 + 2/5

= 24/ 35