Please help??? An explanation would help too and the answers

the first, (f+g)(x) is f(x) + g(x)

calculating it like:

x² + 7x + (8 -x²)

= x² + 7x + 8 -x²

= 7x + 8

you just writ it down as a calculation and calculate it. i hope that helps understanding the concept/basic idea. please let me know wich ones you need more help with.

edit1: the domain is the range of possibilities wich x we can plug into the new equation

12/11c

or

12

c

11

1. 3.4/4

2. 0.8/7

3. 0.5 x 3

4. 0.9 x 6

5. 10.8

6. 2.35

7. 0.567

8. 9.35

9. 0.02

10. 0.06

11. 0.16

12. 0.42

13. 0.63

14. 5.6

15. 8.1

16. 9.9

17. 0.28

18. 0.48

19. 0.27

20. 0.49

21. 0.45

22. 0.72

23. 0.9

24. 0.88

25. 0.75

26. 0.16

27. 0.328

28. 0.495

29. 0.72

30. 1.068