A. ( 29 + 58 ) + ( 218 + 57 ) + ( 2033 - 226 ) = 12 - 13...

4.

a. (

29

+

58

) + (

218

+

57

) + (

2033

-

226

) =

12

-

13

+

13

=

12

b. (

12

+

13

+

61

) – (

14

18

-

161

-

321

-

641

-

1281

) = 1 -

1281

=

127128

c*. (1 -

12

) + ( 1 -

56

) + (1-

1211

) + (1-

1920

) + (1 -

2930

)

=

1.21

+

2.31

+

3.41

+

4.51

+

5.61

=

11

-

12

+

12

-

13

+

13

-

1