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Wednesday, March 28, 2012

hw #8-2 Factoring Frenzy!!!

see the MathChamber Unit8 page for homework

4 comments:

  1. Could someone help me on #27, pg 495.
    I filled in the formula for area of a square (s^2) with 15x and got 225x^2.
    Then I put 5x into the formula for the area of a circle and got π(25x^2).
    From there I was just confused on how to subtract the two. I think something in my expressions went wrong.

    ReplyDelete
    Replies
    1. YUP! Did you draw a picture? To get the area of the frame, you need to subtract the area of the circle (since it is supposedly a cut-out) from the area of the square.

      Using your correct calculations from above:

      225x^2 - 25πx^2

      This is a simplified expression. Since we are algebraic mechanics, we are asked to write the answer in factored form. Do you see any common factors? I do. 25 and x^2, yes?

      "Pull out" the 25 and the x^2 and you get:

      25x^2(9 - π)

      Delete
  2. I had problems with #27 and also #33 i wasnt too sure on. can someone help?

    ReplyDelete
    Replies
    1. #33)

      t^2(t + 1) - t(2t^2 - 1)

      Distribute

      t^3 + t^2 - 2t^3 + t

      Combine Like Terms

      -t^3 + t^2 + t

      Capeesh?

      Had they asked for factored form, you could have factored out a '-t' to obtain:

      -t(t^2 - t - 1)

      Fascinating, eh?

      Delete