Results 1 to 7 of 7

Math Help - Rewriting Equations

  1. #1
    Senior Member vaironxxrd's Avatar
    Joined
    Nov 2010
    From
    USA
    Posts
    426
    Thanks
    1
    Awards
    1

    Rewriting Equations

    I have to solve for y . No given values
    I already tried solving this but I just can't solve the fraction. I tried multiplying the reciprocal on both sides but I don't know if I have to make 20 a fraction
     -\frac{5}{4}&x+&5y&=20
    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
    28

    Re: Rewriting Equations

     -\frac{5}{4}x+5y=20

     5y=20+\frac{5}{4}x

     y=\frac{20+\frac{5}{4}x}{5}

     y=4+\frac{x}{4}
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member vaironxxrd's Avatar
    Joined
    Nov 2010
    From
    USA
    Posts
    426
    Thanks
    1
    Awards
    1

    Re: Rewriting Equations

    Quote Originally Posted by pickslides View Post
     -\frac{5}{4}x+5y=20

     5y=20+\frac{5}{4}x

     y=\frac{20+\frac{5}{4}x}{5}



     y=4+\frac{x}{4}
    Whats going on with the fraction in the second step? is it being simplified by 5?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,740
    Thanks
    480

    Re: Rewriting Equations

     -\frac{5}{4}x+5y=20

     5y=20+\frac{5}{4}x

    multiply every term by 4 to clear the fraction ...

     20y=80+5x

    divide every term by by 20 ...

    y = 4 + \frac{x}{4}
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Senior Member vaironxxrd's Avatar
    Joined
    Nov 2010
    From
    USA
    Posts
    426
    Thanks
    1
    Awards
    1

    Re: Rewriting Equations

    Quote Originally Posted by skeeter View Post
     -\frac{5}{4}x+5y=20

     5y=20+\frac{5}{4}x

    multiply every term by 4 to clear the fraction ...

     20y=80+5x

    divide every term by by 20 ...

    y = 4 + \frac{x}{4}
    I got everything until you have to divide by 20.

    80/20 = 4
    5x/20 = Lost
    Follow Math Help Forum on Facebook and Google+

  6. #6
    -1
    e^(i*pi)'s Avatar
    Joined
    Feb 2009
    From
    West Midlands, England
    Posts
    3,053
    Thanks
    1

    Re: Rewriting Equations

    Quote Originally Posted by vaironxxrd View Post
    I got everything until you have to divide by 20.

    80/20 = 4
    5x/20 = Lost
    \frac{5x}{20} = \dfrac{5x}{5 \times 4}

    Cancel 5 to get x/4
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Senior Member vaironxxrd's Avatar
    Joined
    Nov 2010
    From
    USA
    Posts
    426
    Thanks
    1
    Awards
    1

    Re: Rewriting Equations

    Quote Originally Posted by e^(i*pi) View Post
    \frac{5x}{20} = \dfrac{5x}{5 \times 4}

    Cancel 5 to get x/4
    Got it , I din't know I could do that,
    Thanks
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Rewriting cos
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: January 25th 2011, 01:52 PM
  2. Rewriting a ODE in -t
    Posted in the Differential Equations Forum
    Replies: 7
    Last Post: September 30th 2010, 08:27 AM
  3. I need help with a proof (by rewriting)
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: November 9th 2009, 06:51 AM
  4. Rewriting Equations
    Posted in the Algebra Forum
    Replies: 3
    Last Post: July 21st 2009, 08:45 AM
  5. Rewriting Expression
    Posted in the Algebra Forum
    Replies: 4
    Last Post: April 12th 2007, 10:12 PM

Search Tags


/mathhelpforum @mathhelpforum