## algebra 1 Question

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• We are on lesson 3.4 and I have a question for my daughter. Problem 15 she got the answer -4+6x but the answer in the solutions book is 6x-4. Problem 17 she
Message 1 of 5 , Feb 2, 2012
We are on lesson 3.4 and I have a question for my daughter.

Problem 15 she got the answer -4+6x but the answer in the solutions book is 6x-4. Problem 17 she got the answer -13c+13 but the solutions book had the answer listed as 13-13c. Is there a rule we missed on which order the answer should be in. On Problem 14 the answer in the book is -4z-7 so my thought of an answer not being allowed to start with a negative number is just a thought :)

I am thinking we are missing a rule for how we are to distribute and commute etc. Is there an easy answer. What is the rhyme and reason on how the answer is displayed.

Karen
• Hi Karen, Good question! Your daughter s answers are completely correct. They are just not in the book s simplest written form. You can have a negative in
Message 2 of 5 , Feb 2, 2012
Hi Karen,

Good question!  Your daughter's answers are completely correct.  They are just not in the book's "simplest" written form.  You can have a negative in front but you should know that the books and standard tests may have it as your solution book does.  So...she would want to realize that they are equivalent and be able to recognize that as well as show her answer that way too, if preferred or asked.  Hope that helps.  As a former math teacher, I was not concerned with which way the student wrote it as long as the signs were correct. :)

Lori

Original question...

We are on lesson 3.4 and I have a question for my daughter.

Problem 15 she got the answer -4+6x but the answer in the solutions book is 6x-4. Problem 17 she got the answer -13c+13 but the solutions book had the answer listed as 13-13c. Is there a rule we missed on which order the answer should be in. On Problem 14 the answer in the book is -4z-7 so my thought of an answer not being allowed to start with a negative number is just a thought :)

I am thinking we are missing a rule for how we are to distribute and commute etc. Is there an easy answer. What is the rhyme and reason on how the answer is displayed.

Karen

• Thank you so very much Lori for your answer. I didn t think it mattered but then I didn t want her to be missing a key step that would confuse her or mess her
Message 3 of 5 , Feb 2, 2012
Thank you so very  much Lori for your answer. I didn't think it mattered but then I didn't want her to be missing a key step that would confuse her or mess her up in later lessons. Thank you.

From: MathWithoutBorders@yahoogroups.com [mailto:MathWithoutBorders@yahoogroups.com] On Behalf Of Lori Noel
Sent: Thursday, February 02, 2012 2:41 PM
To: MathWithoutBorders@yahoogroups.com
Subject: [MathWithoutBorders] Re: algebra 1 Question

Hi Karen,

Good question!  Your daughter's answers are completely correct.  They are just not in the book's "simplest" written form.  You can have a negative in front but you should know that the books and standard tests may have it as your solution book does.  So...she would want to realize that they are equivalent and be able to recognize that as well as show her answer that way too, if preferred or asked.  Hope that helps.  As a former math teacher, I was not concerned with which way the student wrote it as long as the signs were correct. :)

Lori

Original question...

We are on lesson 3.4 and I have a question for my daughter.

Problem 15 she got the answer -4+6x but the answer in the solutions book is 6x-4. Problem 17 she got the answer -13c+13 but the solutions book had the answer listed as 13-13c. Is there a rule we missed on which order the answer should be in. On Problem 14 the answer in the book is -4z-7 so my thought of an answer not being allowed to start with a negative number is just a thought :)

I am thinking we are missing a rule for how we are to distribute and commute etc. Is there an easy answer. What is the rhyme and reason on how the answer is displayed.

Karen

• The answers she gave are correct. The two terms that are being added (in the first example) are -4 and 6x. Each term represents a number. The commutative
Message 4 of 5 , Feb 2, 2012
The answers she gave are correct.  The two terms that are being added (in the first example) are -4 and 6x.  Each term represents a number.  The commutative property states that numbers (or variables or expressions representing numbers) can be added in either order.  One thing to watch out for, however, is that the minus sign must "travel" with the number it is attached to.  For instance 6x-4 is NOT equivalent to 4-6x, but it IS equivalent to -4+6x.  (Whether one avoids starting with the negative term is a matter of style only and makes no difference mathematically.)

I hope this helps and is not so detailed as to make it more confusing.

--David Chandler

On Thu, Feb 2, 2012 at 10:55 AM, coman928 wrote:

We are on lesson 3.4 and I have a question for my daughter.

Problem 15 she got the answer -4+6x but the answer in the solutions book is 6x-4. Problem 17 she got the answer -13c+13 but the solutions book had the answer listed as 13-13c. Is there a rule we missed on which order the answer should be in. On Problem 14 the answer in the book is -4z-7 so my thought of an answer not being allowed to start with a negative number is just a thought :)

I am thinking we are missing a rule for how we are to distribute and commute etc. Is there an easy answer. What is the rhyme and reason on how the answer is displayed.

Karen

• Thank you for answering, Lori. I answered from my email before seeing your response. I appreciate having a community of users who can help each other.
Message 5 of 5 , Feb 2, 2012
Thank you for answering, Lori.  I answered from my email before seeing your response.  I appreciate having a community of users who can help each other.
--David Chandler

On Thu, Feb 2, 2012 at 2:13 PM, David Chandler wrote:
The answers she gave are correct.  The two terms that are being added (in the first example) are -4 and 6x.  Each term represents a number.  The commutative property states that numbers (or variables or expressions representing numbers) can be added in either order.  One thing to watch out for, however, is that the minus sign must "travel" with the number it is attached to.  For instance 6x-4 is NOT equivalent to 4-6x, but it IS equivalent to -4+6x.  (Whether one avoids starting with the negative term is a matter of style only and makes no difference mathematically.)

I hope this helps and is not so detailed as to make it more confusing.

--David Chandler

On Thu, Feb 2, 2012 at 10:55 AM, coman928 wrote:

We are on lesson 3.4 and I have a question for my daughter.

Problem 15 she got the answer -4+6x but the answer in the solutions book is 6x-4. Problem 17 she got the answer -13c+13 but the solutions book had the answer listed as 13-13c. Is there a rule we missed on which order the answer should be in. On Problem 14 the answer in the book is -4z-7 so my thought of an answer not being allowed to start with a negative number is just a thought :)

I am thinking we are missing a rule for how we are to distribute and commute etc. Is there an easy answer. What is the rhyme and reason on how the answer is displayed.