Results 1 to 5 of 5

Math Help - I need help solving these rational equations.

  1. #1
    Newbie
    Joined
    Oct 2009
    Posts
    12

    I need help solving these rational equations.

    first
    solve for x
    1/x-1 + 1/x =5
    Last edited by Pre-Calc; October 27th 2009 at 02:10 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    29
    Quote Originally Posted by Pre-Calc View Post
    1/x-1 + 1/x =5
    Hey cobber, please consider how you post these problems. For starters pls post 1 problem per thread and show your working to this point. Better we help you learn rather than do the problems for you.

    My other concern is the lack of brackets. Why? Well which is your problem?

    \frac{1}{(x-1)} + \frac{1}{x} =5

    or

    \frac{1}{x}-1 + \frac{1}{x} =5

    I'm guessing the first one, but how can I be sure?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Oct 2009
    Posts
    12
    the first one is my problem im new to this forum so i didn't no how to put it that way sorry.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    -1
    e^(i*pi)'s Avatar
    Joined
    Feb 2009
    From
    West Midlands, England
    Posts
    3,053
    Thanks
    1
    Quote Originally Posted by Pre-Calc View Post
    the first one is my problem im new to this forum so i didn't no how to put it that way sorry.
    First things first, clear up some domain issues by saying x \in \mathbb{R} \: , \: x \neq 0\,,\,1

    <br />
\frac{1}{(x-1)} + \frac{1}{x} =5<br />

    Take \frac{1}{x} from both sides and rewrite 5 as \frac{5x}{x} (this is allowed because x \neq 0)

    \frac{1}{x-1} = \frac{5x-1}{x}

    Cross multiply: x = (5x-1)(x-1)

    Expand, simplify and solve the quadratic

    Spoiler:
    5x^2-6x+1 = x \: \rightarrow \: 5x^2-7x+1 = 0

    x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}

     = \frac{7 \pm \sqrt{(-7)^2-(4)(5)(1)}}{(2)(5)} = \frac{7 \pm \sqrt{29}}{10}
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Oct 2009
    Posts
    12
    ty.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Solving Rational Equations
    Posted in the Algebra Forum
    Replies: 1
    Last Post: September 20th 2011, 04:19 AM
  2. Solving Rational Equations
    Posted in the Algebra Forum
    Replies: 15
    Last Post: June 21st 2011, 07:15 PM
  3. Solving Rational equations.
    Posted in the Algebra Forum
    Replies: 4
    Last Post: November 8th 2009, 05:28 PM
  4. Solving rational equations
    Posted in the Algebra Forum
    Replies: 1
    Last Post: October 10th 2008, 03:26 AM
  5. solving rational equations
    Posted in the Algebra Forum
    Replies: 4
    Last Post: July 6th 2008, 01:25 PM

Search Tags


/mathhelpforum @mathhelpforum