Expert: Richard J. Raridon - 7/24/2010

Question
1. f(x) = 5x - 3
Find f(7)


20  32
54  14

2. g(x) = 6(x + 2)
Find g(3)


65  24
30  20

3. h(x) = 4x + 3
Find h(-5)


-17  -8
-35  2

4. f(x) = x2 + 7x
Find f(4)


118  44
36  32

5. f(x) = x2 + 7x
Find f(-3)


-30  -27
-24  -12

6. f(x) = -3x + 9

 
g(x) = 8x + 7

Find f(x) + g(x)


5x + 16  -24x2 + 63
21x  11x + 16

7. f(x) = -3x + 9

 
g(x) = 8x + 7

Find f(g(x))


-24x - 12  21x
-24x2 + 63  -24x + 16

8. f(x) = -3x + 9

 
g(x) = 8x + 7

Find g(f(x))


-24x + 16  -24x + 79
5x + 16  -24x2 + 63

9. f(x) = 4x

 
h(x) = -7x - 5

Find h(f(3))


-3  -68
-89  -26

10. f(x) = 4x + 2

 
h(x) = -7x - 5

Find f(h(x))


-28x - 18  - 3x - 3
- 28x - 3  -28x2 - 10

11. f(x) = 4x + 2

 
h(x) = -7x - 5

Find f(x) - h(x)


11x - 3  11x + 7
-11x - 3  -3x - 3

12. f(x) = 4x + 2

 
h(x) = -7x - 5

Find f(7) + h(2)


-24  -44
-9  11

13. g(x) = 3x2 + 4x - 8
Find g(-3)


-47  31
-31  7

14. g(x) = 3x2 + 4x - 8
Find g(4)


20  48
56  32

15. f(x) = 12x - 7
Find f(3)


29  15
57  -48

16. f(x) = 12x - 7
Find f(-7)


-133  -91
-35  -178

17. g(x) = -8x + 15
Find g(2)


-1  -14
-136  -46

18. f(x) = 12x - 7

 
g(x) = -8x + 15

Find f(g(3))


105  -115
20  82

19. f(x) = 12x - 7

 
g(x) = -8x + 15

Find f(2) + g(4)


38  -92
-212  0

20. h(x) = 2x3 - 5x2
Find h(3)


99  54
-12  9

21. h(x) = 2x3 - 5x2
Find h(-5)


-375  -75
-80  -175

22. f(x) = 15 - 6x

 
g(x) =  3/5x       


Find f(g(-10))


51  14+16/25(14 AND sixteen twenty fifths)


-54  15

23. f(x) = 15 - 6x

 
g(x) =  3/5x       


Find g(f(x))


9 - 10x             9 -18/5x


1/25  -  1/10x       15-18/5x    

  

24. f(x) = 15 - 6x

 
g(x) =  3 x       
5

Find g(f(5))


-3  -9
-41  23/50



25. f(x) = 15 - 6x

 
h(x) =  3/4x - 5


Find f(h(6))


-9  18
-3  6 7/8"Basically 6whole number combined with 7/8ths"


26. g(x) = 8x2 - 5
Find g(-3)


67  43
-53  -33

27. f(x) = -3x

 
g(x) = 8x2 - 5

Find g(f(-2))


43  -53
283  -293

28. h(x) = x2 + 7x
Find h(-11)


-55  -198
44  -99

29. h(x) = x2 + 7x
Find h(-5)


-45  -25
-60  -10

30. f(x) = x3 - x2 - 3x + 5
Find f(4)


41  3
65  13

31. f(x) = 2x3 - 3x2

Find f(-3)

-81 (what i got)
32. f(x) = 2x + 9

g(x) = -5x +12
Find f(g(8))


-44 (what i got)
33. f(x) = 4x-3

g(x) = x2-2
Find f(4)-g(5)


-14 (what i got)
34. f(x) = 4x-3

g(x) = x2-2
Find f(3a-4)


12a-19 (what i got)
35. f(x) = x - x2
Find f(0), f (-1), f(2), and f(-2)


0;-2;-2; and -6  (what i got)

Answer
I ordinarily don't work this many for one person but these were so simple that I could do most of them in my head.  
1. 32
2. 30
3. -17
4. 44
5. -12
6. 5x+16
7. -24x-12
8. -24x-79
9. -89
10. -28x-18
11. 11x+7
12. 11
13. 7
14. 56
15. 29
16. -91
17. -1
18. -115
19. 0
20. 9
21. -375
22. 51
23. 9 - (18/5)x
24. -9
25. 18
26. 67
27. 283
28. 44
29. 10
30. 41
31. -81
32. g(8)=-28, f(-28)=-47
33. -10
34. ok
35. ok