Assignment 26

course Mth 151

??L?????????g??????assignment #026

Your work has been received. Please scroll through the document to see any inserted notes (inserted at the appropriate place in the document, in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.

026. `query 26 College Algebra 11-21-2007

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08:35:41 5.4.12 What is [ (10+7) * (5+3) ] mod 10 and how did you get your result?

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RESPONSE --> (17*8) = 136 (17*8) = 6(Mod10) confidence assessment: 2

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08:39:02 ** x mod 10 is the remainder when x is divided by 10. So [ (10+7) * (5 + 3) ] mod 10 = ( 17 * 8) mod 10 = 136 mod 10 = 6, since 136 / 10 leaves remainder 6. **

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RESPONSE --> self critique assessment: 2

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08:53:50 query 5.4.20 2 / 3 on 5-hour clock What is 2 divided by 3 on a 5-hour clock, and how did you obtain this result?

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RESPONSE --> I'm sorry but I'm not sure how to work it. I looked at my DVD and couldn't find how to do it, looked in the section on 5 hour clock and in section 5.4 but I can't figure it out so I am going to move on to the answer so I can see how to work it. confidence assessment: 0

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09:00:11 ** You have to turn this one into a multiplication problem to get the correct answer. In decimal numbers, for example, 60 / 20 = 3 because 3 * 20 = 60. Whatever you get when you divide 2 by 3, when you multiply it by 3 you get 2. That is, if 2 / 3 = x, then 3 x = 2. So what would you multiply by 3 to get 2 on a 5-hour clock? It turns out that 3 * 4 = 2. So it follows that 2 / 3 = 4. **

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RESPONSE --> Oh, okay. You would mutiply both sides by 3 getting 2 = 3x and then work it from there. 3x=2 3(4) = 2 (mod5) self critique assessment: 2

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09:14:38 query 4.4.42 (3 - 27) mod 5 What is (3 - 27) mod 5, and how did you reason out your result?

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RESPONSE --> 3 + (-27) = 3 + (-2) = 3 + 3 = 6 = 1 (mod 5) I fixed an inverse chart of 5 and found that 3 was the inverse of -2. confidence assessment: 2

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09:16:35 ** (3-27) mod 5 = -24 mod 5. You would go all the way around around backwards 5 complete times to get -25, then move forward 1 to get to -24. That would put you at 1 on the actual clock. **

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RESPONSE --> I got the same answer just in a different way. I did the inverse chart, is that okay? self critique assessment: 2

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09:25:58 query 5.4.20 Pos Integer solns (5x-3) = 7 (mod 4)

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RESPONSE --> 5x - 3 = 7 5x - 10 = 0 5x + 2 = 0 x = 2 5(2) + 2 = 0 (mod 4) confidence assessment: 2

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09:27:10 ** The solutions have to be integers, and the mod makes a difference in the algebra. 7 (mod 4) is 3. Since (5x - 3) mod 4 = 7 mod 4, (5x - 3) mod 4 must be 3. For x = 1, 2, 3, 4, ..., the expression 5x - 3 takes values 2, 7, 12, 17, 22, 27, 32, 37, ... . These numbers, when divided by 4, give remainders 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, ... . Thus every fourth number, mod 4, is equal to 3. This starts with the second number, which occurs when x = 2. Every fourth number, starting with 2, gives us the sequence 2, 6, 10, 14, ... 2 is the first solution, 4 is the difference between solutions. Thus x can be any element in the set {2, 6, 10, 14, . . . }. The general term of this sequence is 2 + 4 n. So we can also say that x = 2 + 4 n, where n = 0, 1, 2, 3, . . . Checking these results: If n = 0 then x = 2 + 4 * 0 = 2. If n = 1 then x = 2 + 4 * 1 = 6. If n = 2 then x = 2 + 4 * 2 = 10. If n = 3 then x = 2 + 4 * 3 = 14. etc. These are the solutions obtained above to the equation. **

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RESPONSE --> self critique assessment: 2

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09:33:35 query 5.4.30 table for addition mod 7 and properties of operation

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RESPONSE --> + 0 1 2 3 4 5 6 0 0 1 2 3 4 5 6 1 1 2 3 4 5 6 0 2 2 3 4 5 6 0 1 3 3 4 5 6 0 1 2 4 4 5 6 0 1 2 3 5 5 6 0 1 2 3 4 6 6 0 1 2 3 4 5 Closure property & indentity confidence assessment: 2

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09:37:23 ** Your table should read 0 1 2 3 4 5 6 0 0 1 2 3 4 5 6 1 1 2 3 4 5 6 0 2 2 3 4 5 6 0 1 3 3 4 5 6 0 1 2 4 4 5 6 0 1 2 3 5 5 6 0 1 2 3 4 6 6 0 1 2 3 4 5 The operation is closed, since all numbers mod 7 are between 0 and 6. The only numbers on the table are 0, 1, 2, 3, 4, 5, 6. The operation has an identity, which is 0, because when added to any number 0 doesn't change that number. We can see this in the table because the row corresponding to 0 just repeats the numbers 0123456, as does the column beneath 0. The operation is commutative--order doesn't matter because the table is symmetric about the main diagonal.. The operation has the inverse property because every number can be added to another number to get the identity 0: 0+7 = 0, 1+6=0, 2+5=0, 3+4=0. These numbers form pairs of inverses. This property can be seen from the table because the identity 0 appears exactly once in every row. The operation is associative, since for any a, b, c we know that (a + b ) + c = a + ( b + c), and it follows that [ (a + b ) + c ] mod 7 must equal [ a + ( b + c) ] mod 7. **

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RESPONSE --> I didn't put all the properties, but I see in your explanation how they are other properties. self critique assessment: 2

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09:43:17 5.4.33 table for mult mod 4 and properties of operation

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RESPONSE --> * 0 1 2 3 0 0 0 0 0 1 0 1 2 3 2 0 2 0 2 3 0 3 2 2 It is closed, communitative, assocative, indentity and inverse. confidence assessment: 2

Remember when taking a test that just listing the properties is not sufficient; you have to state why each property holds.

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09:49:38 ** The correct table is 0 1 2 3 0 0 0 0 0 1 0 1 2 3 2 0 2 0 2 3 0 3 2 1 For example the row across from 2 is obtained as follows: 2 * 0 = 0 and 2 * 1 = 2, as always. Then 2 * 2 mod 4 = 4 mod 4, which is 0 and 2 * 3 mod 4 = 6 mod 4, which is 2. the operation is closed because the results all come from the set {0, 1, 2, 3} being operated on 1 is the identity because the row and column for 1 both have 0,1,2,3 in that order, so 1 doesn't change a number when multiplied by that number. 0 and 2 lack inverses--they can't be combined with anything else to get 1--so the operation lacks the inverse property. symmetry about the main diagonal implies commutativity associativity follows from associativity of multiplication of real numbers**

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RESPONSE --> I put that it was inverse. I keep getting inverse mixed up. self critique assessment: 2

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&#

Very good work. Let me know if you have questions. &#

end of document

Your work has not been reviewed. Please notify your instructor of the error, using the Submit Work form, and be sure to include the date 11-26-2007.

Good.

`gr9

Assignment 26

course Mth 151

??L?????????g??????assignment #026

Your work has been received. Please scroll through the document to see any inserted notes (inserted at the appropriate place in the document, in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.

026. `query 26

College Algebra

11-21-2007

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08:35:41

5.4.12 What is [ (10+7) * (5+3) ] mod 10 and how did you get your result?

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RESPONSE -->

(17*8) = 136

(17*8) = 6(Mod10)

confidence assessment: 2

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08:39:02

** x mod 10 is the remainder when x is divided by 10.

So [ (10+7) * (5 + 3) ] mod 10 = ( 17 * 8) mod 10 = 136 mod 10 = 6, since 136 / 10 leaves remainder 6. **

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RESPONSE -->

self critique assessment: 2

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08:53:50

query 5.4.20 2 / 3 on 5-hour clock

What is 2 divided by 3 on a 5-hour clock, and how did you obtain this result?

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RESPONSE -->

I'm sorry but I'm not sure how to work it. I looked at my DVD and couldn't find how to do it, looked in the section on 5 hour clock and in section 5.4 but I can't figure it out so I am going to move on to the answer so I can see how to work it.

confidence assessment: 0

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09:00:11

** You have to turn this one into a multiplication problem to get the correct answer.

In decimal numbers, for example, 60 / 20 = 3 because 3 * 20 = 60.

Whatever you get when you divide 2 by 3, when you multiply it by 3 you get 2. That is, if 2 / 3 = x, then 3 x = 2.

So what would you multiply by 3 to get 2 on a 5-hour clock?

It turns out that 3 * 4 = 2. So it follows that 2 / 3 = 4. **

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RESPONSE -->

Oh, okay. You would mutiply both sides by 3 getting 2 = 3x and then work it from there.

3x=2

3(4) = 2 (mod5)

self critique assessment: 2

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09:14:38

query 4.4.42 (3 - 27) mod 5

What is (3 - 27) mod 5, and how did you reason out your result?

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RESPONSE -->

3 + (-27) = 3 + (-2) = 3 + 3 = 6 = 1 (mod 5)

I fixed an inverse chart of 5 and found that 3 was the inverse of -2.

confidence assessment: 2

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09:16:35

** (3-27) mod 5 = -24 mod 5.

You would go all the way around around backwards 5 complete times to get -25, then move forward 1 to get to -24. That would put you at 1 on the actual clock. **

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RESPONSE -->

I got the same answer just in a different way. I did the inverse chart, is that okay?

self critique assessment: 2

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09:25:58

query 5.4.20 Pos Integer solns (5x-3) = 7 (mod 4)

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RESPONSE -->

5x - 3 = 7

5x - 10 = 0

5x + 2 = 0

x = 2

5(2) + 2 = 0 (mod 4)

confidence assessment: 2

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09:27:10

** The solutions have to be integers, and the mod makes a difference in the algebra.

7 (mod 4) is 3.

Since (5x - 3) mod 4 = 7 mod 4, (5x - 3) mod 4 must be 3.

For x = 1, 2, 3, 4, ..., the expression 5x - 3 takes values 2, 7, 12, 17, 22, 27, 32, 37, ... .

These numbers, when divided by 4, give remainders 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, ... .

Thus every fourth number, mod 4, is equal to 3.

This starts with the second number, which occurs when x = 2.

Every fourth number, starting with 2, gives us the sequence 2, 6, 10, 14, ...

2 is the first solution, 4 is the difference between solutions.

Thus x can be any element in the set {2, 6, 10, 14, . . . }.

The general term of this sequence is 2 + 4 n. So we can also say that x = 2 + 4 n, where n = 0, 1, 2, 3, . . .

Checking these results:

If n = 0 then x = 2 + 4 * 0 = 2.

If n = 1 then x = 2 + 4 * 1 = 6.

If n = 2 then x = 2 + 4 * 2 = 10.

If n = 3 then x = 2 + 4 * 3 = 14.

etc.

These are the solutions obtained above to the equation. **

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RESPONSE -->

self critique assessment: 2

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09:33:35

query 5.4.30 table for addition mod 7 and properties of operation

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RESPONSE -->

+ 0 1 2 3 4 5 6

0 0 1 2 3 4 5 6

1 1 2 3 4 5 6 0

2 2 3 4 5 6 0 1

3 3 4 5 6 0 1 2

4 4 5 6 0 1 2 3

5 5 6 0 1 2 3 4

6 6 0 1 2 3 4 5

Closure property & indentity

confidence assessment: 2

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09:37:23

** Your table should read

0 1 2 3 4 5 6

0 0 1 2 3 4 5 6

1 1 2 3 4 5 6 0

2 2 3 4 5 6 0 1

3 3 4 5 6 0 1 2

4 4 5 6 0 1 2 3

5 5 6 0 1 2 3 4

6 6 0 1 2 3 4 5

The operation is closed, since all numbers mod 7 are between 0 and 6. The only numbers on the table are 0, 1, 2, 3, 4, 5, 6.

The operation has an identity, which is 0, because when added to any number 0 doesn't change that number. We can see this in the table because the row corresponding to 0 just repeats the numbers 0123456, as does the column beneath 0.

The operation is commutative--order doesn't matter because the table is symmetric about the main diagonal..

The operation has the inverse property because every number can be added to another number to get the identity 0: 0+7 = 0, 1+6=0, 2+5=0, 3+4=0. These numbers form pairs of inverses. This property can be seen from the table because the identity 0 appears exactly once in every row.

The operation is associative, since for any a, b, c we know that (a + b ) + c = a + ( b + c), and it follows that [ (a + b ) + c ] mod 7 must equal [ a + ( b + c) ] mod 7. **

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RESPONSE -->

I didn't put all the properties, but I see in your explanation how they are other properties.

self critique assessment: 2

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09:43:17

5.4.33 table for mult mod 4 and properties of operation

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RESPONSE -->

* 0 1 2 3

0 0 0 0 0

1 0 1 2 3

2 0 2 0 2

3 0 3 2 2

It is closed, communitative, assocative, indentity and inverse.

confidence assessment: 2

Remember when taking a test that just listing the properties is not sufficient; you have to state why each property holds.

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09:49:38

** The correct table is

0 1 2 3

0 0 0 0 0

1 0 1 2 3

2 0 2 0 2

3 0 3 2 1

For example the row across from 2 is obtained as follows: 2 * 0 = 0 and 2 * 1 = 2, as always. Then 2 * 2 mod 4 = 4 mod 4, which is 0 and 2 * 3 mod 4 = 6 mod 4, which is 2.

the operation is closed because the results all come from the set {0, 1, 2, 3} being operated on

1 is the identity because the row and column for 1 both have 0,1,2,3 in that order, so 1 doesn't change a number when multiplied by that number.

0 and 2 lack inverses--they can't be combined with anything else to get 1--so the operation lacks the inverse property.

symmetry about the main diagonal implies commutativity

associativity follows from associativity of multiplication of real numbers**

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RESPONSE -->

I put that it was inverse. I keep getting inverse mixed up.

self critique assessment: 2

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&#

Very good work. Let me know if you have questions. &#

end of document

Your work has not been reviewed.

Please notify your instructor of the error, using the Submit Work form, and be sure to include the date 11-26-2007.

Good.

&#

Let me know if you have questions. &#