### Scribe Post for Friday March 19

Friday, March 19, 2010
Hey 9 -05! Today we basically just corrected our tests. Here are some of the questions that most people had trouble with.

(I'm not completely sure if these are the right ones, so if they aren't, please let me know)

19. Write a simplified expression for the area of this figure. What is the area of the figure?

A = 5y (7y - 4) multiply 5y by 7y and -4

5y (7y) = 35y^2 (y^2 means y squared)

5y (-4) = -20y

= 35y^2 - 20y

The area of the figure is 35y^2 - 20y square units. « simple sentence answer

20. Apply the distributive property to simplify 2x (x-4) - 3x (x - 4).

2x (x-4) -3x (x-4)
=2x^2 - 8x - 3x^2 + 12x remember that it's -3x (x-4). Multiply 2x(x-4) and -3x (x-4)
=2x^2 - 3x^2 - 8x + 12x then you combine like terms
=-x^2 + 4x

21. A pool table is twice as long as it is wide. If the area of the pool table is 2.88m^2, what are the dimensions of the table?

I find it helpful to draw a diagram

A = lw

2.88 = 2w(w)

2.88 = 2w^2

2.88/2 = 2w^2/2

1.44 = w^2

then you find the square root

1.2 = w

The length is 2 times the width

l = 2w The dimensions are length = 2.4m and width = 1.2m.

l = 2 (1.2)

l = 2.4

We also went over these two questions.

(x + 5)^2 = (x +5) (x+5)

= x^2 +5x + 5x +25

= x^2 +10x + 25

2. 3(x+2)^2 = 3 (x+2) (x + 2)

= (3x + 6) (x+2)

= 3x^2 + 6x + 6x + 12

= 3x^2 + 12x + 12

Homework:

Get ready Chapter 6

go to www.mathplayground.com and play "zogs"

Well, that's all for my scribe. If I missed anything, please let me know. PLEASE COMMENT! (also, I have no idea who hasn't done a scribe yet, so if you haven't, YOU'RE NEXT :P) Okay, bye.

#### 3 comments:

Zerlina905 said...

Nice scribe Kristin! I really like your use of colours and nice pictures. Good job in explaining the test. I don't think you made any errors. So great job again!

angela905 said...

Good job Kristin! Great use of colours, and pictures. You explained it very well. Good job again! :)

shaneille 9-05 said...

Great job Kristin! Great job explaining the questions from the test! Although at the end everything is a bit crowded, you maybe could space it out a bit. Overall Great Scribe!