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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,631

**Elementary Exercises**

1. 3x = 9

2. 3x+2 = 8

3. x-2 = 11

4. 2x-2 = 8

5 x+7 = 5

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**mikau****Member**- Registered: 2005-08-22
- Posts: 1,504

**More exercises**

Cool stuff, mathsisfun. But what exactly are we supposed to do? Is someone supposed to give the answers or are we supposed to just post questions?

6. 5/x - 2 = 8

7. 3x - 5 = 7x

8. 3x +16 = 7x

9. (5 + 2x)/2 = 3x

10. x/2 -7 = - x/9

A logarithm is just a misspelled algorithm.

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,631

Thanks, mikau!

A few can be solved fully, some can have answers using the "hide" tag, and some have no answers at all. This is to help people practice for fun or for exams.

It is totally fine to just post questions. The answers can be given by others, possibly even people asking "is this right?"

I am happy with this to be in full "forum" style, chatty, and with mulitple ways to solve if applicable. I think this will help make the exercises "come alive".

But I think it also good to keep the exercises "on topic", so I will come along later and edit these posts, probably incorporate them in the "sticky" topic.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,631

**Answers**

1.

Start with: 3x = 9

Divide both sides by 3: x = 3

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

Great idea, MathsIsFun. One question though - Are we limited to answer only a certain amount of questions at a time? Also, do we have to wait for questions to be answered before starting new ones?

4. We use the inverse.

8 + 2 = 10

From this we know that 10 / x = 2

We do the inverse again.

10 / 2 = x

x = 5

5. Inverse.

5 - 7 = x

x = -2

6. Again, the inverse.

8 + 2 = 10

Now we know that 5 / x = 10

5 / 10 = x

5 / 10 = 0.5

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,631

Well, we are still feeling our way on this new section.

At this stage people are free to answer or basically do whatever they want, but a moderator is likely to come along and delete some posts if there are too many answers.

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**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

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**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

**More Excercises**

11. x - 6 = 5

12. 62 = 6x + 6x + 2

13. 4(-1 + 5x) = -44

14. 2x + 5 = -19

15. -4 + 4x = x - 37

16. 14 = x + 10

17. x + 3 = 6

18. -2 + x = 3

19. x / 3 = 4

20. x + 1 = 10

21. 2x + 10 = 2

22. 7x + 8 = 8

23. 10 + 5x = 50

24. 4x + 1 = 41

25. 6 + 4x = -26

26. -5 - 6x + x = 0

27. 2 - 2x - x = -7

28. -12 = -x + 5x + 8

29. 2 = - 3x - x + 10

30. 3 - 2x - 2x = 35

31. -6x - 3 = 5x - 3

32. -5x + 9 = 9 + 2x

33. -2 + 5x = 4x - 13

34. -6x + 5 = 29 - 4x

35. 5 - 2x = -7x - 35

36. -3(6 + 5x) = -183

37. 4(-6x + 9) = 324

38. 5(7 - x) = 5

39. -5(-2x + 9) = -125

40. 3(6x + 2) = 114

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

11. x - 6 = 5

x = 5+ 6

= 11

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**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

**More Excercises**

41. x - 3 = -6

42. 9 = x + 8

43. x + 1 = -10

44. 7 = x + 9

45. 5 + x = 13

46. -4 = x + 2

47. 0 = x - 9

48. -3x = -3

49. 8 = x + 2

50. x + 10 = -1

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**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

**More Excercises**

51. 16 = x + 9

52. x + 7 = 7

53. 3x = -9

54. 3x = 33

55. -8 = x - 8

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

26. -5 - 6x + x = 0

-5x = 5

x = 5/-5

= -1

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

27. 2 - 2x - x = -7

2 - 3x = -7

-3x= -7 -2

-3x = - 9

x = -9 / -3

= 3

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

28. -12 = -x + 5x + 8

-12 -8 = -x + 5x

-20 = 4x

x = -20/4

= -5

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**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

All correct - Well done.

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

29. 2 = - 3x - x + 10

2-10 = -3x -x

-8 = -4x

x = -8 / -4

= 2

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

Devanté

i love math....heheheheh

*Last edited by nikconsult (2006-08-16 00:20:53)*

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**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

Correct.

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

32. -5x + 9 = 9 + 2x

-5x -2x = 9-9

-7x = 0

x = 0/-7

= 0

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

33. -2 + 5x = 4x - 13

-2 + 13 = 4x - 5x

11 = -x

x = -11

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

34. -6x + 5 = 29 - 4x

-6x + 4x = 29-5

-2x = 24

x = 24/-2

= -12

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**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

All correct. Well done again, nikconsult.

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**Kurre****Member**- Registered: 2006-07-18
- Posts: 280

hm you could put the answer after every exercise in a hide button. like this:

7x+12=2-3x

*Last edited by Kurre (2006-08-18 21:17:19)*

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

How u do like that Kurre

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

35. 5 - 2x = -7x - 35

5 + 35 = -7x + 2x

40 = -5x

x = 40/ -5

= -8

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