## Monday, February 27, 2012

### Solving Equations

3x = 0.6 <-- you need to divide both sides by 3

3x/3 = 0.6/3

x=0.2

LS RS check ;

3x=0.6

3(0.2)

0.6

x/a = b <-- you can multiply (a)(b)

x/5 = 0.3

5(x/5) = 5(0.3)

x = 1.5

LS RS check ;

x/5 = 0.3

x = 1.5/0.3

a/x = b

3.3/x = 1.1

x(3/3) = 1.1x

3.3/1.1 = 1.1x/1.1

3=x <--You can do it like this or ...

x=3 <-- this is the more proper way

LS RS ;

3.3/x = 1.1

3.3/3

1.1

2x = 3/4

Divide 2 by itself = 3/4 . 2/1

x = 3/4 x 1/2 . 2/1 x 1/2 makes 0.

3/4 x 1/2 = 3/8

LS RS check ;

2x = 3/4

2/1(3/8) =

6/8

3/4.

another way to the previous question is ...

2x/1 = 3/4

(2x)(4) = 3

8x/8 = 3/8

x = 3/8

-2 1/2x = -3 1/2 <-- make into a proper fraction

-5/2x = -7/2

x = -7/-5

another way of doing it ;

-5/2x = -7/2

-5/2 x -2/5

x = 7/5

and another way ...

-5/2x = -7/2

-5x(2) = 2(-7)

-10x/-10 = -14/-10

x = 14/10 or 7/5

YOUR HOMEWORK:

Read Pages 292-300

Do SYU

Do CYU#3

Practise, APPLY ALL

Extend 3/5

8.1 Homework Book

## Tuesday, February 14, 2012

### More Practice on Chapter 7

First we were given a question to find the area of rectangle with a missing piece using polynomials.

There are two ways to figuring out the area of this shape. First way is to break up the shape into 3 pieces, and add Areas 1 and 2, and subtract area 3.

The second way is to pretend the missing piece is there (area 1) so it makes a whole rectangle, then subtract area 2 (missing piece) to area 1. I chose to do this method because it seemed like a faster way for me.

Show your work:

l = 8x - 4 + 4x + 9 = 12x +5

w = 6x + 2 + 3x - 5 = 9x - 3

A1 = lw

= (12x + 5)(9x -3)

= (12x)(9x) + (12x)(-3) + (5)(9x) + (5)(-3)

= 108x^ - 36x + 45x - 15

A2 = lw

= (8x - 4)(3x -5)

= (8x)(3x) + (8x)(-5) + (-4)(3x) + (-4)(-5)

= 24x^ - 40x -12x + 20

= 24x^ - 52x + 20

A1 - A2

= 108x^ + 9x -15 - (24x^ - 52x + 20)

= 108x^ +9x - 15 -24x^ +52x - 20

= 84x^ + 61x -35

Therefore, the area of the shape is 84x^ + 61x - 35.

The second question was a triangle. This was much simpler because it didn't contain a missing piece.

A = bh/2

= (8x +4)(5x)/2

= (8x)(5x) + (4)(5x)

= 40x^ + 20x/2

= 40x^/2 + 20x/2

= 20x^ + 10x

The area of the triangle is 20x^ + 10x.

The third question was to find the width of the rectangular prism.

V = lwh

48x³ = (2x)(w)(3x)

48x³ = 6x^

w = 48x³/6x^

w = 8x

The width of the rectangular prism is 8x.

The fourth question is similar to the first one, except with different values. Again, I used the A1-A2 method.

Step 1

Step 2

Step 3

The area of the shape is 26x^ - 35x - 12.

The fifth question is finding the ratio of the rectangle to the circle. This won't be on the test but it's better to know it now for future references.

r = d/2

r = 6x/2

r = 3x

rectangle / circle

= lw / pi r^

= 6x(12x) / pi(3x)^

= 72x^/pi 9x^

= 8 / pi

The last question was to find the ratio of the small circle to the large circle.

So/Lo = pi r^/pi r^

= pi(2x)^/pi(4x)^

= 4x^/16x^

= 4/16

= 1/4

Solve:

1. 3(5x + 3) - (10x - 6)

= 15x +9 - 10x + 6

= 5x + 15

2. (1/2t)^ 3t

= (1/2t)(1/2t)(3t)

= 1/4t^(3t)

= 3/4t³

Remember:

Always use the FOIL(First, Outside, Inside, Last) method when multiplying

Only add/subtract like terms

When subtracting polynomials, (-) before the 2nd polynomial means to multiply (-1) to each term. (Change each sign to its opposite)

Study, go on Mangahigh, and practice!

The next person to do the scribe will be Jocelle Garcia!

## Monday, February 13, 2012

### Diorella's Blog Post

The next person to do the blog will be..

**Marie Domingo.**

## Thursday, February 9, 2012

### Mark C's Multiplying Binomials & Dividing Post

**Click here for a website that teaches and reviews more things about the FOIL method**

**DIVISION**

**HOMEWORK:**

**Read pp. 272-274**

**CYU #1 & 2**

**Practice: Odd/Even**

**Apply: All**

**Extend: 2 of 3**

**Homework Book: 7.3**

**Green Sheets: 7-10 #1-7**

## Wednesday, February 8, 2012

### Ryan's math blog post

## Tuesday, February 7, 2012

### Multiplying and Dividing Monomials.

**Multiplying monomials:**

To start off we did a four questions they were:

(3)(2)= 6

(-4)(4)= -16

(-7)(-3)=21

(5)(-6)= -30

then we got to harder questions

3(2x)= 6x *"this means 3 groups of 2x"*

*we had to model it after wards*

* *

-4(3x)=-12x

(-3y)(-2x)= 6xy

*"I think that the answer turned out to be xy because if you multiply two numbers with different variables you're answer has to have a degree of two."*

* *

(3x)(-3x) = -9x^2 (squared)

*"This is one became squared because if you multiply two variables and they are both the same you get 2nd degree or squared"*

Dividing Monomials:

Similar to Multiplication we had to do some questions.

6/3= 3

-8/4=(-2)

16/-8= -2

-15/-3= 5.

6x/3= 2x

How to model division monomials.

very similar to the multiplication model.

-4xy/-2x= 2y

"how?''

*'' since there are two x's both of them get canceled out, leaving you with just the variable y''*

-6y^2/2y= -3y

*"since there were two y's on the first one, one gets canceled out and only one is left"*

Not everything can get modeled for example:

-6^3/ -2x= 3x^2

"The reason for that is because we don't have anything to represent a cube."

* ***HOMEWORK!!!**

**7.1 read pp 254-259**

**CYU#2**

**Practise : odd/even**

**Apply: all**

**Extend : 24,26,27**

**Homework book :7.1**

**" The next scribbler is Ryan Bautista"**