Results 1 to 5 of 5
Like Tree1Thanks
  • 1 Post By HallsofIvy

Math Help - problem with sequence and means

  1. #1
    Member
    Joined
    Jun 2010
    From
    Zewail University - Cairo - Egypt
    Posts
    141

    problem with sequence and means

    the A.S mean of two no.s : 8,2x^2 exceeds their positive G.M by 9 .Find X
    i got it 5, -5 is that right?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Jun 2010
    From
    Zewail University - Cairo - Egypt
    Posts
    141

    Re: problem with sequence and means

    problem with sequence and means-p240612_1255.jpg
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Mar 2012
    From
    Sheffield England
    Posts
    440
    Thanks
    76

    Re: problem with sequence and means

    Quote Originally Posted by mido22 View Post
    the A.S mean of two no.s : 8,2x^2 exceeds their positive G.M by 9 .Find X
    i got it 5, -5 is that right?
    (8+2x^2)/2 -9 = root (16x^2) So4+x^2 -9 =4x So x^2-4x-5=0 (x-5)(x+1)=0 So x=5 (cant be -1 in this question)
    If x=5 2x^2= 50 So the two numbers are 8 and 50 (which you can check are correct)
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member
    Joined
    Jun 2010
    From
    Zewail University - Cairo - Egypt
    Posts
    141

    Re: problem with sequence and means

    but -5 is also correct
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,982
    Thanks
    1645

    Re: problem with sequence and means

    Yes, mido22, x= 5 and x= -5 are the answers.
    Thanks from mido22
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 0
    Last Post: December 14th 2011, 05:02 AM
  2. Replies: 2
    Last Post: August 24th 2010, 02:10 AM
  3. Airthmetic-geometric means problem?
    Posted in the Algebra Forum
    Replies: 1
    Last Post: November 25th 2007, 08:31 AM
  4. does anyone know wht this means?
    Posted in the Calculus Forum
    Replies: 4
    Last Post: November 15th 2007, 05:21 PM
  5. Help with Means
    Posted in the Statistics Forum
    Replies: 1
    Last Post: October 25th 2007, 07:53 AM

Search Tags


/mathhelpforum @mathhelpforum