### Scribe Post for February 26, 2010

Though there were a lot of people away on friday, there was still math class, and homework of course. By the way, GOOD JOB TO ALL THE BAND PEOPLE (:

First of all, Mr.B had to set up that projector thingy that always takes some time, but yeah .. we helped (;

After he got it all set up, we went to get our textbooks.

We went over questions 1-4 on Pg. 190. (Explore Adding or Subtracting Polynomial Expressions)

Here they are:

Now, you may be wondering about Question #4 ...

But even if you're not, you still need to know why some people are. (including me, at first)

Mr.B got into a huge discussion over this specific question, and here's why:

55x + 30 - (22x + 20) is NOT the same as 55x + 30 - 22x + 20

And that goes back to BEDMAS.

Brackets are always first, but according to the second expression, there are none, so you solve in order from left to right.

As Mr.B said, "COMMON ERROR."

Also Mr.B taught us this:

hint-hint, PUT THIS IN YOUR NOTES.

In Question #4, where it says 55x + 30 - (22x + 20) or 55x + 30 - 22x - 20, do you understand how they are equal?

Do you know why one is positive/plus, and one is negative/minus?

Well if you don't know:

- (22x + 20)

^

that negative sign means, the opposite of everything in the brackets.

Therefore, - (22x + 20) = - 22x - 20.

If you remember, on friday morning Mr.B came into our classroom, and told me that theres going to be a lot of notes for the scribe.

So I thought, there were just a lot of minor notes, but actually, there was just one major one.

It was really confusing at first, but the more he explained, the more I understood.

Plus, everyone else's explanations (;

So that was basically all we did today. I hope you understood my work. If I have any mistakes, please comment and tell me. And if you have any other questions, feel free to ask me, or Mr.B, which ever you prefer.

And before I forget, Mr.B also assigned some homework:

Pg. 191-194 Read 5.3 Examples (Textbook)

Pg. 195 Read Key Ideas, Add to notes (Textbook)

Pg. 195 Check Your Understanding #1-3 (Textbook)

Pg. 196-198 ALL Practice and Apply (Textbook)

NO EXTEND

TEST: Either next Tuesday/Wednesday, so do your homework and STUDY (;

The next scribe will be....

ZERLINA (;

Thanks again for reading my scribe, do your homework, study, and leave a comment.

AND ASK QUESTIONS if you have any.

SMILE (:

### Scribe Post for February 24, 2010

a) 2w + s

b) w stands for the number of wins, s stands for the number of shootout losses

c)20-12-4=4 losses

d) 2w+s

2(12)+4

24+4

28

*Just replace the **variables** with the given numbers.

e) 2x5+18=28

2x9+10=28

*The combinations are for team B, and has to equal 28.

Then, we had a review about polynomials, their **coefficients**, variables, and **exponents**.

Here's a chart about that (we had to fill in the coefficients, variables, and exponents):

After that, Ms. Yoo, started us on **unit 5.2**. Which is * equivalent expressions*. But we talked about

**like terms**first. What are like terms? Like terms are terms that differ only by their numerical coefficients.

*Variables, and it's power stay the same. Coefficients changes however.

examples:

3x and -2x

6y² and 3y²

-5xy and -2 xy

17 and 12

Here's are other examples featuring the variable x:

-1x=-x

+x= x

-x²=-x²

+1x²=x²

*Mathematicians are lazy, they don't like writing 1 in front of a variable.

Next, we had to identify like terms:

(like terms are colour coded, dark green, and blue)

a) 5b² 3bc **-2b ** 7c **6b**

b) **3x² ** 4xy **-2x² 7x²** 1/2 y

c) **3pq ** **11 ** -4q² ** -3** ** pq**

Then, we were combining like terms. (the variables and coefficients are bolded, the constants are "slanted", while variables with higher power than 1 are left with regular font)

a) **4x-2x***+3-6*

2x-3

*4x-2x= 2x, +3-6= -3

b)** **2x²**+3x** *-1*+x²**-4x***-2*

3x²-x-3

c) k-2k²+3+5k²-3k-4

-3k²-2k-1

*-Always start with the highest degree (power)*

*-Try to gather like terms first*

After, we had to simplify like terms.

1) x²-(-3x) +4+7x²-8x-6

x²+7x²**-8x+3x***+4-6 (<= work should look like that)*

8x²-5x-2

explanation: 7x²+x² is 8x², while -8x+3x is -5x, and 4+(-6) is -2

2) **-x-5x**+(-3x²*)-9***-2x***+7*

-3x²-8x-2

3) 4x³+6x²+6x-1+5x³-x²-(-9)

9x³+5x²+6x+8

That's all we did in class. Hope I covered everything. Here's the homework:

-5.2 Extra Practice

-5.2 Workbook

-2 sheets (double sided)

-journal

-textbook work (since we don't have class tomorrow because of the Tec Voc tour)

-5.2 Mathlink (Mr. B didn't assign this, so do it if you have time)

-COMMENT ON MY POST!

*By the way, Friday's scribe is **Melanie** (since there's no math class tomorrow)

### Scribe Post for February 23, 2010

### Scribe Post for February 19, 2010

Sorry I couldn't really do anything on this. I just had to get it done, I'll do better next time Mr. B and 9-05!

### Monday, February 22, 2010

**stash-its back**!

*****For anyone in hope of handing in part of your stash-it... or if you were planning on trying to hand in your mathlinks for bonus marks (like me)...you're

**to late**.

**reviewing our Chapter 4 Unit Test!**Nicky pointed out that the test was in fact out of

**47**instead of

**48**! The question that I think most people had difficulty on would probably be question #28.

**15cm**across between any two opposite sides. Create a scale drawing of your design, using a scale factor of

**2 : 5**.

**x**".

**15cm**in the actual, so it goes with the

**5**.

**x**" Is part of the image, so it will go with the

**2**

**5**to

**15**, you multiply 5 by 3

**proportional**, you must do the same to the other side. So

**2 x 3 = 6**

**6cm**.

**number of sides**a regular polygon has, is the

**amount of equivalent**and

**equiangular triangles**the polygon is made up of. To find the angles of these triangles, we need to divide 360° by 6, since that is how many triangles we will be using. That gives us triangles with

**60° angles**. Since you know all that information, all you then have to do is draw the straight horizontal line measuring 6cm, the diagonal lines using a 60° angle between the lines, and lastly connect the sides. Sorry if you didn't quite understand that, if you need any help just

**ask**in class.

__HOMEWORK__**LINDA**! (:

### Scribe Post for February 8, 2010

Here is an example:

the scale of a map is 2in= ___mi

map: 5in

actualy: 32.5mi

This is the first method you could use in finding the answer:

Here is another way in solving this question:

So you see, either way you solve it, you still get the same answers.

After that, we just worked on the other sheets he gave to us.

**MATH HOMEWORK**

1. Math Journal

2. Check that blog Mr. B showed us

3. Look at the videos and stuff thats on the grade nine homepage

4. Stash it

- All Math Links including Intro and Wrap it up

- One of your tests signed

-Math Journal

- Self Assessment

- Chapter 4 Blog Problems

THANK YOU FOR LOOKING AT MY POST :) I'm sorry if I took a long time to make this post, but I hope you like it! :) And also, I'm not sure how to make the picture bigger so I'm sorry if its too small. ANYWAYS, the next scribe is... dun dun dun......

**DEAN**(: (:

### Scribe Post :)

**Similarity and Proportions**..

**aren't very hard to understand.**

*Similarity and Proportions***NOT**congruent to the others because they are all different.

**- They have to have matching or congruent angles that are equal.**

*Similar Figures*If we were to flip the shape around we will see if they truly are congruent to one another.

The first angle we are looking at is equal or corresponding to its other angle.

If we do that to all the other angles, they should all be the same as there corresponding angles.

**btw**: 01 = 10 and 81 = 18

All the angles match their corresponding angles they are congruent.

So at least for the angles of the shape they are equal. But now we have to look at the

*..*

**sides**For the

*they have to form a proportion. You can find the proportion in several different ways. I'll show you one way.*

**sides****btw:**01= 10 and 81 = 18

We can compare to get a proportion. So i'll call 18 and 13.5 side A, and i'll call 10 and 7.5 side B. Then we could compare 18 and 13.5 ( both of the side A's). So now we want to see if thats congruent to 10 and 7.5 (both of the side B's). They are congruent to each other. Because if we

**divide**18 and 13.5 we get 1.3 repeating and if we

**divide**10 and 7.5 we also get 1.3 repeating. So the two ratios represent the same amount.

So these figures really are similar because there sides are proportional.

If we tested out the other sides we'd see the same thing. 8 to 8 is the same thing as 6 to 6 because they are all representing a ratio of 1.

Well thats my scribe! :) Wow, I acutally understood things while doing this -_-". Backe, I hope youe happy! AHAHA :) see you guys soon ♥ oh and tell me if have mistakes!!! :D

### Scribe Post for January 29, 2010

**scale diagrams**,

**enlargements**and

**reductions**. In my opinion I thought some questions were easy, and some were quite hard. I didn't do so well on that test, but next test I will do better! :)

I'm gonna be choosing one question from each heading ex. multiple choice, short answer etc.

Multiple Choice

1. A scale of 2:5 means

a) there are 2 units of the image for every unit of actual size

b) there are 2 units of the image for every 5 units of actual size

c) there are 5 units of the image for every unit of actual size

d) there are 5 units of the image for every 2 units of actual size

ANSWER: B

Completion

7. The enlargement of an image is 3 times the size of the original. The value 3 represents the _________.

ANSWER: Scale Factor

Short Answer

11. In a drafting class, students must create reductions of actual objects for technical diagrams. Barry wants to use a scale factor of 0.25 to draw a machine part. If the actual object has a width of 100cm, what should the width of Barry's drawing be?

ANSWER:

100 x 0.25 = 25

The width of Barry's drawing should be 25cm.

Anyways, that's all the different parts to the test. There was only 16 questions. Please comment and help me make my post better! :)