Total Pageviews

Friday, May 13, 2011

hw #11-1 SING IT!! Factors Cancel, Terms Don't... Factors Cancel, Terms Don't!!

UNIT 11 is up and running on MathChamber... I'm sure you were suffering withdrawal symptoms!

We didn't discuss the concept of EXCLUDED VALUES in class today... you will need to understand it.  Simply stated, now that we have algebraic fractions with variables in the ORIGINAL denominator, there are specific values of the variable that would cause the ORIGINAL denominator to equal ZERO... a mathematical "no-no" as you know-know (I just crack me up!).

So, a simple example would be (x-2)/(x-7)... This expression can be evaluated for all real numbers x, except x=7.

So when you simplify an expression like (x-2)(x-4)/(x-4), it simplifies to x-2 for all real numbers where x<>2
... when you simplify an expression like (x+2)/(x^2+5x+6), it simplifies to 1/(x+3) for all real numbers where x<>-2,-3, since the ORIGINAL expression in the denominator could be factored to (x+2)(x+3).

YOU can do this... Ca-peesh??

hw #11-1 pg 655 #1-7, 9-21 Odd, #29,33,42

HAVE FUN!!!
Posted by at

25 comments:

  1. AnonymousMay 15, 2011 at 4:28 PM

    how do you do number 29? i am soo confused!!

    ReplyDelete
  2. Mr. ChamberlainMay 15, 2011 at 9:44 PM

    The volume of a rectangular prism can be described as "the area of the base times the height":

    V=Ah where V is the volume, A is the area of the base, and h is the height

    If we didn't know the height, we could solve the formula for h and get:

    h=V/A, yes?

    So, in #29, YOU KNOW THE VOLUME AND YOU KNOW THE AREA AND YOU WANT TO FIND THE HEIGHT.

    The expression for the volume is given, and the expression for the area should be l*w or w(2w+5)

    so:
    h=(2w^3+7w^2+5w)/[w(2w+5)]

    You can factor the 'w' out of the numerator AND then you have a quadratic, which I'll be you can factor as well... HAVE FUN!!

    ReplyDelete
  3. AnonymousMay 15, 2011 at 10:02 PM

    Thanx!!

    ReplyDelete
  4. AnonymousMay 16, 2011 at 3:09 PM

    i dont understand #42

    ReplyDelete
  5. Paul C.May 16, 2011 at 3:48 PM

    I had a touch of 103 fever and bronchitis on friday, and have just about zero idea of what on earth I should do to solve these problems.

    1. What does it mean in the book's explanation by ^1 and 1under the number?

    2. It looked like they were distributing, but how would that be done in a fraction
    3. Oy!

    Please halp

    ReplyDelete
  6. Mr. ChamberlainMay 16, 2011 at 5:47 PM

    if anyone would like to chat, lmk

    ReplyDelete
  7. AnonymousMay 16, 2011 at 5:57 PM

    That surprise Conga Line scared me! Especially when I had to be the leader!

    -Anon..

    ReplyDelete
  8. AnonymousMay 16, 2011 at 6:01 PM

    If any questions come up, I would like to chat!

    ReplyDelete
  9. Mr. ChamberlainMay 16, 2011 at 6:01 PM

    for #42, you'll need the formulas for surface area and volume for the respective solids... don't know 'em? check out the mathchamber nj/ask prep link and click on the grade8 ref. page.

    ReplyDelete
  10. Mr. ChamberlainMay 16, 2011 at 6:02 PM

    what's so surprising about a conga line?

    ReplyDelete
  11. Mr. ChamberlainMay 16, 2011 at 6:09 PM

    PW, I don't understand your comments/questions... can u b more specific? let me know if you want to chat...

    ReplyDelete
  12. Mr. ChamberlainMay 16, 2011 at 6:11 PM

    the book is using the distributive property to factor expressions... the factors create BIG FAT ONES that divide out (aka cancel), hence simplifying the rational expressions (rational expressions are simply algebraic fractions)

    ReplyDelete
  13. AnonymousMay 16, 2011 at 6:13 PM

    I don't understand "State any excluded values." What does that mean?

    ReplyDelete
  14. AnonymousMay 16, 2011 at 6:17 PM

    Could -1 be a factor of 5? Trying to do #2..

    ReplyDelete
  15. AnonymousMay 16, 2011 at 6:19 PM

    I don't know how to come up with an expression for #3!

    ReplyDelete
  16. AnonymousMay 16, 2011 at 6:32 PM

    What are excluded values? Please help!

    ReplyDelete
  17. AnonymousMay 16, 2011 at 6:35 PM

    Help with #6! Isn't it yes?

    ReplyDelete
  18. AnonymousMay 16, 2011 at 7:03 PM

    Can (2a+3)/4 be further simplified?

    Can we go on Chat?

    ReplyDelete
  19. Mr. ChamberlainMay 16, 2011 at 7:04 PM

    let's chat for awhile...

    ReplyDelete
  20. Paul C.May 16, 2011 at 7:57 PM

    I think I have a very basic understanding of the concept, but I don't understand why in the second step of each example there are 1s next to the numerator & denominator. Wouldn't you just divide it out, like we did before this unit?

    ReplyDelete
  21. Mr. ChamberlainMay 16, 2011 at 8:22 PM

    Well, dividing out means 1 over 1, right?

    ReplyDelete
  22. Mr. ChamberlainMay 16, 2011 at 8:23 PM

    go to mathchamber and join us in a chat

    ReplyDelete
  23. Mr. ChamberlainMay 16, 2011 at 8:28 PM

    I discuss excluded values up above in the blog post heading.

    ReplyDelete
  24. AnonymousMay 16, 2011 at 8:52 PM

    help with # 3
    ( I hate word problems.)

    ReplyDelete
  25. Mr. ChamberlainMay 16, 2011 at 9:00 PM

    i'll have to see you in class... sorry good night!

    ReplyDelete

Subscribe to: Post Comments (Atom)