Results 1 to 8 of 8

Math Help - Literal Formula Question

  1. #1
    Newbie
    Joined
    Jul 2011
    Posts
    9

    Literal Formula Question

    Hi, I have two (basic) questions that I cant seem to understand. I'm in a self taught course where I learn everything from a book so it might have not explained everything fully. Question #1. p = 2hw/(s+1) solve s. My answer to the question is s = -1 + 2hw/p however I've been told the correct answer is s = -p + 2hw/p. My question is, why are there two P's now instead of 1? Can anyone explain that to me? Thank you.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,234
    Thanks
    27

    Re: Literal Formula Question

    I think your answer is better.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,386
    Thanks
    1476
    Awards
    1

    Re: Literal Formula Question

    Quote Originally Posted by Robert12 View Post
    Hi, I have two (basic) questions that I cant seem to understand. I'm in a self taught course where I learn everything from a book so it might have not explained everything fully. Question #1. p = 2hw/(s+1) solve s. My answer to the question is \color{blue} s = -1 + 2hw/p however I've been told the correct answer is \color{red}s = -p + 2hw/p. My question is, why are there two P's now instead of 1? Can anyone explain that to me? Thank you.
    Your answer is correct

    The given answer is not.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Jul 2011
    Posts
    9

    Re: Literal Formula Question

    Interesting, this isnt the first time I've seen that however. One of the questions in my book: M = 2T/g+a for a is similar, the answer given is a = 2T - gM/M. My answer: a = 2T - gM If this is another mistake could anyone provide an example where I could get an answer of two of the same variable from one incase I see it on a test? Thank you for the quick responses.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,234
    Thanks
    27

    Re: Literal Formula Question

    Quote Originally Posted by Robert12 View Post
    Interesting, this isnt the first time I've seen that however. One of the questions in my book: M = 2T/g+a
    This one is quite simple, solve for 'a'

    M = 2T/g+a

    M - 2T/g = a

    And we are done.

    What do you mean by

    Quote Originally Posted by Robert12 View Post
    If this is another mistake could anyone provide an example where I could get an answer of two of the same variable from one
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,386
    Thanks
    1476
    Awards
    1

    Re: Literal Formula Question

    Quote Originally Posted by Robert12 View Post
    Interesting, this isnt the first time I've seen that however. One of the questions in my book: M = 2T/g+a for a
    Given M=\frac{2T}{g+a} that is the same as
    \begin{align*}  g+a &= \frac{2T}{M} \\  a &= \frac{2T}{M}-g\end{align*}
    Follow Math Help Forum on Facebook and Google+

  7. #7
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1

    Re: Literal Formula Question

    Just double check whether or not the given answers are the solutions
    to the following (should you have had parenthesis around certain numerators and denominators).

    p=\frac{2hw}{s+1}

    p(s+1)=2hw\Rightarrow\ ps+p=2hw\Rightarrow\ ps=2hw-p

    s=\frac{2hw-p}{p}

    which is the same as

    s=\frac{2hw}{p}-\frac{p}{p}


    For the 2nd one....

    M=\frac{2T}{g+a}

    M(g+a)=2T\Rightarrow\ Mg+Ma=2T

    Ma=2T-Mg

    a=\frac{2T-Mg}{M}
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Newbie
    Joined
    Jul 2011
    Posts
    9

    Re: Literal Formula Question

    Wow, thank you Archie and everyone else. It makes complete sense now. You were right about the parenthesis which is why my answers were formatted a bit differently. I'll keep it in mind when solving questions like that again.

    Edit: I can see there are 3 different answers for the 2nd question. I'm going to by the one Archie has since its in my solutions but is there generally more then one way to solve questions like that? Or was this just a simple mistake of not using parenthesis?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Literal Equations Calculator
    Posted in the Math Software Forum
    Replies: 1
    Last Post: September 22nd 2011, 06:19 PM
  2. Literal Equation help
    Posted in the Algebra Forum
    Replies: 5
    Last Post: October 28th 2010, 05:00 AM
  3. Literal fraction
    Posted in the Algebra Forum
    Replies: 2
    Last Post: April 24th 2009, 06:03 AM
  4. Literal Equations
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 18th 2009, 07:34 PM
  5. Literal Equations
    Posted in the Advanced Algebra Forum
    Replies: 7
    Last Post: January 8th 2006, 04:34 PM

Search Tags


/mathhelpforum @mathhelpforum