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## #1 2006-07-16 11:08:25

MathsIsFun
Registered: 2005-01-21
Posts: 7,657

### Basic Algebra

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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## #2 2006-07-16 11:47:06

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

### Re: Basic Algebra

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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## #3 2006-07-16 15:22:18

MathsIsFun
Registered: 2005-01-21
Posts: 7,657

### Re: Basic Algebra

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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## #4 2006-07-16 15:28:32

MathsIsFun
Registered: 2005-01-21
Posts: 7,657

### Re: Basic Algebra

1.
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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## #5 2006-07-16 19:01:43

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

### Re: Basic Algebra

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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## #6 2006-07-17 18:37:58

MathsIsFun
Registered: 2005-01-21
Posts: 7,657

### Re: Basic Algebra

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.

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

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## #7 2006-07-26 20:00:51

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

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## #8 2006-07-30 19:09:27

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

### Re: Basic Algebra

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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## #9 2006-08-05 00:22:33

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

11. x - 6 = 5
x = 5+ 6
= 11

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## #10 2006-08-05 07:12:55

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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## #11 2006-08-06 22:10:43

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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## #12 2006-08-14 11:29:39

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

### Re: Basic Algebra

26. -5 - 6x + x = 0
-5x = 5
x = 5/-5
= -1

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## #13 2006-08-14 11:32:00

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

### Re: Basic Algebra

27. 2 - 2x - x = -7
2 - 3x = -7
-3x= -7 -2
-3x = - 9
x = -9 / -3
= 3

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## #14 2006-08-14 11:34:20

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

### Re: Basic Algebra

28. -12 = -x + 5x + 8
-12 -8 = -x + 5x
-20 = 4x
x = -20/4
= -5

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## #15 2006-08-14 19:38:14

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

### Re: Basic Algebra

All correct - Well done.

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## #16 2006-08-16 00:18:08

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

### Re: Basic Algebra

29. 2 = - 3x - x + 10
2-10 = -3x -x
-8 = -4x
x  = -8 / -4
= 2

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## #17 2006-08-16 00:19:16

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

### Re: Basic Algebra

Devanté
i love math....heheheheh

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

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## #18 2006-08-17 20:21:59

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

Correct.

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## #19 2006-08-18 04:42:51

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

### Re: Basic Algebra

32. -5x + 9 = 9 + 2x
-5x -2x = 9-9
-7x = 0
x = 0/-7
= 0

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## #20 2006-08-18 04:45:46

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

### Re: Basic Algebra

33. -2 + 5x = 4x - 13
-2 + 13 = 4x - 5x
11 = -x
x = -11

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## #21 2006-08-18 04:49:23

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

### Re: Basic Algebra

34. -6x + 5 = 29 - 4x
-6x + 4x = 29-5
-2x = 24
x = 24/-2
= -12

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## #22 2006-08-18 04:56:13

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

### Re: Basic Algebra

All correct. Well done again, nikconsult.

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## #23 2006-08-18 21:17:02

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

### Re: Basic Algebra

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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## #24 2006-08-18 22:11:47

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

### Re: Basic Algebra

How u do like that Kurre

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## #25 2006-08-18 22:13:59

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

### Re: Basic Algebra

35. 5 - 2x = -7x - 35
5 + 35 = -7x + 2x
40 = -5x
x = 40/ -5
= -8

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