Results 1 to 5 of 5

Math Help - Quick Polynomial simplifying question

  1. #1
    Junior Member
    Joined
    Jan 2008
    Posts
    69

    Quick Polynomial simplifying question

    Hey guys,
    Just a quick one.. brain freeze on what to do in this case..

    =3-2(8x^2-1)^2
    Now, will I apply the exponent first, or the 2? And if apply the exponent first, what will I multiply the 2 by.. the entire product of the exponent?

    I seem to remember from my math laws that you have to expand the brackets first, but I am unsure if this includes the 2 outside the bracket..

    Thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Jan 2009
    Posts
    108
    expand, then multiply each term of the entire product by 2
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Jan 2008
    Posts
    69
    Thanks..

    wow, and really basic, but my brain just isn't working..

    3-2(64x^4-16x^2+1) (You would multiply everything in the brackets by positive 2, Correct?)

    =3-128x^4 -32x^2 -2
    = -128x^4-32x^2+1 (Correct?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Mar 2007
    Posts
    1,240
    Quote Originally Posted by Slipery View Post
    =3-2(8x^2-1)^2
    What came before the "equals" sign? What were the instructions?

    I think you were supposed to "simplify" or "expand" the polynomial expression. If so, the order of operations says that you have to apply exponents first, so the squaring on the parentheses (to multiply out the polynomial squaring) comes before doing the multiplication in front of the parentheses.

    . . . . . (8x^2\, -\, 1)^2

    . . . . . (8x^2\, -\, 1)(8x^2\, -\, 1)

    . . . . . (8x^2)(8x^2)\, +\, (-1)(8x^2)\, +\, (8x^2)(-1)\, +\, (-1)(-1)

    . . . . . 64x^4\, -\, 16x^2\, +\, 1

    Then you deal with the multiplication out front:

    . . . . . -2(64x^4\, -\, 16x^2\, +\, 1)

    . . . . . -128x^4\, +\, 32x^2\, -\, 2

    Then deal with the addition:

    . . . . . 3\, -\, 128x^4\, +\, 32x^2\, -\, 2

    . . . . . -128x^4\, +\, 32x^2\, +\, 1

    So your final answer is indeed correct. Good work!
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Jan 2008
    Posts
    69
    Thank you!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Real quick question about simplifying!
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: April 20th 2010, 03:21 AM
  2. [SOLVED] quick question on simplifying
    Posted in the Algebra Forum
    Replies: 3
    Last Post: July 18th 2009, 12:05 AM
  3. quick simplifying question
    Posted in the Algebra Forum
    Replies: 9
    Last Post: July 9th 2009, 03:34 AM
  4. Replies: 2
    Last Post: July 6th 2008, 06:34 PM
  5. quick simplifying question
    Posted in the Algebra Forum
    Replies: 1
    Last Post: April 9th 2008, 12:06 PM

Search Tags


/mathhelpforum @mathhelpforum