This Blog exists for the collective benefit of ALL Algebra students. While the posts are usually specific to Mr. Chamberlain's class, any and all "algebra-ticians" are welcome. The more specific your question (including your own attempts to answer it) the better.

Wednesday, September 28, 2016

hw #2-R Review - ALL ABOARD THE ALGEBRA ROLLERCOASTER!!

We will have a combination Chapter 1 Test & Chapter 2 Quiz on Thurs/Fri Oct 6th/7th

hw #2-R Practice Packet (see email of Canvas for problem list)

I'm sort of confused with #30 on page 6. -7(n+3)-8(1+8n) -7n-21-8+64n (distributive property) wouldn't -7n+64n= 57n? I got 57n-29, and I don't get what I did wrong. Please help?

Mr.C in the packect on pg. 7 question 7 I don't understand how you got 15 because everytime I do it i end up getting -3 or 1. (Btw I'm so, so, so, so sorry if I woke you up this late I just was really struggling on this one question)

Hey Nightowl, it would have been a real hoot if you included the problem in your comment, but I'll answer it now since I have to go eat some worms before the sun comes up!

The problem is (next time YOU provide this!): (v+9)/3 = 8 I'm writing the problem this way because I'm typing, but it reveals an interest situation... since the FRACTION BAR is a grouping symbol there are VIRTUAL parens around both numerator and denominator.

I decided to make a video to help you out. I have posted it as "NEW!" to MathChamber Academy Unit 2, but I'll provide the link here as well. I urge you to visit MC Academy and make sure you are getting all of the help you need.

Mr.C I am having trouble with problem 20 on pg.9. The problem is -5(1-5x)+5(-8x-2)=-4x-8x and I know x=-5 but I can't figure out how to get there. Please help.

The first thing your going to want to do is find the answer on the simpler side so -4x-8x. Once you solve that you can inset the value of x on the left side and then solve.

A personal recommendation I have is to do 5x and -8x first before distributing as it is easier to do a big number times a small number rather than a big number times a big number. Hope this helps.

Please see this "doozie" of a video... when watching the video, please pause at appropriate spots to see if you can finish the problem before you watch the completed problem "play out."

http://www.screencast.com/t/AoAbQTkCJ

This video is now available on MathChamber Academy, listed as:

So the problem is 7/4 - (-1/2) and you have to solve this with a difference maker. The difference maker is using the difference to find the answer. So what you'e trying to do here is find the answer of what is 7/4 minus -1/2. Then you simplify the problem so it is a + sign rather than 2 negative signs and find what is 7/4 after moving 1/2 to the right.

I appreciate your assistance Mr. McDuck, but this is NOT what I want you to do... you are describing the "cute-sie" little Keep-change-change method, which works, of course, but does nothing to increase your UNDERSTANDING of what a DIFFERENCE actually means.

I'll post a video on this shortly... but you should be able to do it simply with paper and pencil on a number line.

Let's do this: 7/4 - (-1/2) Read this as "the difference between 7/4 and -1/2" More specifically, this can be read as "How much more or less is 7/4 compared to -1/2." Mark 7/4 on a number line. Mark -1/2 on the same number line. Clearly 7/4 is to the right of -1/2, so it's "more" right? So that means our result will be positive. Agreed??

How much more? Well, a quick inspection of YOUR diagram reveals that the total distance between -1/2 and 7/4 consists of two sub-segments, one from -1/2 to zero, and one from zero to 7/4.

Add those two segments together (you'll have to remember how to find a common denominator from Mr. McGillicuddy's class) and you now have identified the DIFFERENCE between 7/4 and -1/2, and you will express this difference as a positive number, since 7/4 is more.

If you were given the problem -1/2 - 7/4, you could have used the same diagram that you just made, however you would have designated the difference as a negative number.

7/4 - (-1/2) = 9/4 -1/2 - 7/4 = -9/4

Could you have gotten the right answer for the original problem using the "++" method? Yes. But you would not have a clear understanding of what you are doing and it would not assist you as you begin scaling the long and steep ladder that is high school mathematics.

Well, think about it,,, is it possible that 7-4x could be equal to -9? Assuming that IS possible, can you tell me what -(-9) is? i.e. the opposite of -9 is?

Sorry its early Mr. C., but I'm stuck on the two step and multi step problems and I don't understand how to do them. Even after watching one of your videos. I don't see how x=0 in problem 3, Please help!

I am having trouble with the under lining technique that we have to do on the five homework problems pages 5 through 6. I looked though the videos and couldn't find anything about it.

Hey Spooderman, The under lining technique is when you underline like terms with the same amount of underlines. Confusing? Here's an example: (-5)+(7h)+(-9) since -9 and -5 are "like terms" they would both be underlined once.

INCLUDING THE SYMBOL IN FRONT OF THEM!!!!!

(-9)+(-5) is -14. Since there are no "like terms" for 7h, you leave it alone. The answer is -14+7h.

But lets say that there was the term 5h. Since this is the second "like terms", you would underline it twice. Please let me know if this helped at all.

Like terms share the same variable to the same exponent... they can have different coefficients

5x and 9x are like terms 5x^2 and 9x are NOT like terms... they share the same variable but the exponent is different 9x and -9x are like terms... they are also OPPOSITES, so they will always sum to zero!!

I'm sort of confused with #30 on page 6.

ReplyDelete-7(n+3)-8(1+8n)

-7n-21-8+64n (distributive property)

wouldn't -7n+64n= 57n?

I got 57n-29, and I don't get what I did wrong. Please help?

The math gods would articulate this problem as follows:

DeleteRemove 7 sets of (n+3) AND Remove 8 sets of (1 + 8n)

Your first removal resulted in -7n-21

YOUR second removal resulted in -8+64n ???

If you are removing 8 sets of 1, that is -8

Wouldn't removing 8 sets of 8n result in -64n??

Do you see your error?

Can you tell me how the expanded expression (after the distributive prop was applied) s/h read?

This is what I have been calling "distributing the negative"... it takes practice to get the hang of it.

Can we combine like terms for trying to find the value of x

ReplyDeleteI think the answer is YES... but you would need to give me an example...

DeleteDo you have to write the POEs in order?

ReplyDeleteYou should write them next to the equation steps as you use them... see the videos, ok?

DeleteIt can be tough to do with three toes, but I have confidence in you!!

Mr.C in the packect on pg. 7 question 7 I don't understand how you got 15 because everytime I do it i end up getting -3 or 1. (Btw I'm so, so, so, so sorry if I woke you up this late I just was really struggling on this one question)

ReplyDeleteHey Nightowl, it would have been a real hoot if you included the problem in your comment, but I'll answer it now since I have to go eat some worms before the sun comes up!

DeleteThe problem is (next time YOU provide this!):

(v+9)/3 = 8

I'm writing the problem this way because I'm typing, but it reveals an interest situation... since the FRACTION BAR is a grouping symbol there are VIRTUAL parens around both numerator and denominator.

I decided to make a video to help you out. I have posted it as "NEW!" to MathChamber Academy Unit 2, but I'll provide the link here as well. I urge you to visit MC Academy and make sure you are getting all of the help you need.

http://www.screencast.com/t/TC6YZela

Time to getsk me some worms... YUM-MMMM!

Mr.C I am having trouble with problem 20 on pg.9. The problem is -5(1-5x)+5(-8x-2)=-4x-8x and I know x=-5 but I can't figure out how to get there. Please help.

ReplyDeleteThe first thing your going to want to do is find the answer on the simpler side so -4x-8x. Once you solve that you can inset the value of x on the left side and then solve.

DeleteA personal recommendation I have is to do 5x and -8x first before distributing as it is easier to do a big number times a small number rather than a big number times a big number. Hope this helps.

Please see this "doozie" of a video... when watching the video, please pause at appropriate spots to see if you can finish the problem before you watch the completed problem "play out."

Deletehttp://www.screencast.com/t/AoAbQTkCJ

This video is now available on MathChamber Academy, listed as:

NEW! 2-4 Variable on Both Sides "Doozie"

Mr.C I am having trouble with #30. (1-2) I don't know where to start.

ReplyDeleteSo the problem is 7/4 - (-1/2) and you have to solve this with a difference maker. The difference maker is using the difference to find the answer. So what you'e trying to do here is find the answer of what is 7/4 minus -1/2. Then you simplify the problem so it is a + sign rather than 2 negative signs and find what is 7/4 after moving 1/2 to the right.

ReplyDeleteI appreciate your assistance Mr. McDuck, but this is NOT what I want you to do... you are describing the "cute-sie" little Keep-change-change method, which works, of course, but does nothing to increase your UNDERSTANDING of what a DIFFERENCE actually means.

DeleteI'll post a video on this shortly... but you should be able to do it simply with paper and pencil on a number line.

Let's do this:

7/4 - (-1/2)

Read this as "the difference between 7/4 and -1/2"

More specifically, this can be read as "How much more or less is 7/4 compared to -1/2."

Mark 7/4 on a number line. Mark -1/2 on the same number line. Clearly 7/4 is to the right of -1/2, so it's "more" right? So that means our result will be positive. Agreed??

How much more? Well, a quick inspection of YOUR diagram reveals that the total distance between -1/2 and 7/4 consists of two sub-segments, one from -1/2 to zero, and one from zero to 7/4.

Add those two segments together (you'll have to remember how to find a common denominator from Mr. McGillicuddy's class) and you now have identified the DIFFERENCE between 7/4 and -1/2, and you will express this difference as a positive number, since 7/4 is more.

If you were given the problem -1/2 - 7/4, you could have used the same diagram that you just made, however you would have designated the difference as a negative number.

7/4 - (-1/2) = 9/4

-1/2 - 7/4 = -9/4

Could you have gotten the right answer for the original problem using the "++" method? Yes. But you would not have a clear understanding of what you are doing and it would not assist you as you begin scaling the long and steep ladder that is high school mathematics.

Here's the video...

Deletehttp://www.screencast.com/t/f9RoONfUfbz

You'll also find it on Unit 1 of MathChamber Academy!

what is procedural algebra

ReplyDeletenever mind

ReplyDeleteOn page 9 number 12 it says -(7-4x)=9. How can it =9 if there is a - in front of the parentheses?

ReplyDeleteWell, think about it,,, is it possible that 7-4x could be equal to -9? Assuming that IS possible, can you tell me what -(-9) is? i.e. the opposite of -9 is?

DeleteCheck out this video... the problem is:

Delete15 = -2(2t - 1)

It's the same concept... in the problem you specified, I hope you realize that the "leading negative" is really just -1 in disguise, right?

oops... I forgot to include the link!!

Deletefor this equation: 15 = -2(2t - 1)

http://www.screencast.com/t/vpknewPcqas

ohhhh ok

ReplyDeleteMr.C I need more help with combining like terms. I don't understand how to get to some of the answers on page 5 and 6.

ReplyDeleteThis would be a much better question if you listed even just one or two specific problems... not just the problem number either...

DeleteSorry its early Mr. C., but I'm stuck on the two step and multi step problems and I don't understand how to do them. Even after watching one of your videos. I don't see how x=0 in problem 3, Please help!

ReplyDeleteI mean problem 7.

Deletenevermind I think I got it.

DeleteI am having trouble with the under lining technique that we have to do on the five homework problems pages 5 through 6.

ReplyDeleteI looked though the videos and couldn't find anything about it.

this video is about solving an equation, but the first few steps involve combining like terms...

Deletehttp://www.screencast.com/t/AoAbQTkCJ

Hey Spooderman,

ReplyDeleteThe under lining technique is when you underline like terms with the same amount of underlines.

Confusing? Here's an example: (-5)+(7h)+(-9) since -9 and -5 are "like terms" they would both be underlined once.

INCLUDING THE SYMBOL IN FRONT OF THEM!!!!!

(-9)+(-5) is -14. Since there are no "like terms" for 7h, you leave it alone. The answer is -14+7h.

But lets say that there was the term 5h. Since this is the second "like terms", you would underline it twice.

Please let me know if this helped at all.

Thanks Kira it helped me out

DeleteNo problem. Glad I could help!

DeleteMr.Chamberlin when using the Underlining technique to combine like terms are -9x and (+)9x considered like terms???

ReplyDeleteLike terms share the same variable to the same exponent... they can have different coefficients

Delete5x and 9x are like terms

5x^2 and 9x are NOT like terms... they share the same variable but the exponent is different

9x and -9x are like terms... they are also OPPOSITES, so they will always sum to zero!!

How do you do problem 20 on page 9? I am having a lot of trouble and don't know what to do. The question is...

ReplyDelete-5(1-5x)+5(-8x-2)=-4x-8x

This question was asked ABOVE at 8:38am yesterday... please see my answer ABOVE!

DeleteHow Do you do Problem 1 on the Problem set A packet?

ReplyDeleteCan you be a little more specific on what you need help with on the problem? I'm pretty sure I'm not supposed to just show you how to do the problem.

DeleteI already did, Kira... it's on the video!

Deletehttp://www.screencast.com/t/cJRr3aOKe

Thanks Mr.C

DeleteHi Mr. C

ReplyDeleteOn the test question number 6, -8^2 -(-5^2), I answered 39. Here are my steps.

-8^2 -(-5^2)

(-8*-8)-(-5*-5)

64 - 25

39

Can you please clarify what was wrong.

Thank you.

Sincerely,

Trumposaurus Rex (Let's build a wall)

What is synonymous with a negative sign? Multiplying by -1, right?

ReplyDeleteSo let's do a little "Humpty Dumpty" expansion of this expression, ok? ( * is a multiplication "dot")

-8^2 - ( -5^2 )

-1*8^2 - ( -1*5^2)

-1*8*8 - (-1*5*5)

See your mistake, yet?

Thank you very much Mr.C

Delete(Let's build a bigger wall!)