C1 : a) 15. 12- 3. 5. 10
= 15. 12 - 15 . 10
= 15 . ( 12 -10)
= 15. 2
= 30
C2: 15. 12- 3. 5. 10
= 180 - 150
= 30
C1 : b) 45- 9. (13+ 5)
= 45 - 9. 18
= 45 - 162
= -117
C2: 45- 9. (13+ 5)
= 45 - 9 . 13 + 9 . 5
= 45 - 117 + 45
= -117
C1 : c) 29. (19- 13)- 19. (29- 13)
= 29. 6 - 19. 16
= 174 - 114
= 60
C2 : 29. (19- 13)- 19. (29- 13)
=29. 6 - 19.6
= 6. ( 29 - 19 )
= 6.10
= 60