Results 1 to 2 of 2

Math Help - algebra help

  1. #1
    Member
    Joined
    Jan 2008
    Posts
    173

    algebra help

    1) If the average (arithmetic mean) of five consecutive integers is m, what is the product of the greatest and least of these five integers?


    2) If x + y = 11 and xy = 15, find the value of x^2 + y^2.


    3) Find the solution to absolute vavalue of (x ) - 1 = 2x + 1.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member
    Joined
    May 2009
    From
    Zagreb
    Posts
    65
    Quote Originally Posted by sri340 View Post
    1) If the average (arithmetic mean) of five consecutive integers is m, what is the product of the greatest and least of these five integers?


    2) If x + y = 11 and xy = 15, find the value of x^2 + y^2.


    3) Find the solution to absolute vavalue of (x ) - 1 = 2x + 1.
    1) \frac{n_1 + n_2 + n_3 + n_4 + n_5 }{5} = m

    n_1 = n_1
    n_2 = n_1 + 1
    n_3 = n_2 + 1 = n_1 + 2
    n_4 = n_1 + 3
    n_5 = n_1 + 4

    \frac{n_1 + n_1 + 1 + n_1 + 2 + n_1 + 3 + n_1 + 4 }{5} = m

    \frac{5n_1 + 10 }{5} = m

    n_1 + 2 = m

    n_1 = m - 2

    n_5 = n_1 + 4 = m - 2 + 4 = m + 2

    n_1*n_5 = ( m - 2 )( m + 2 ) = m^2 - 4

    2)  x + y = 11

    ( x + y )^2 = 11^2

    x^2 + 2xy + y^2 = 121

    xy = 15

    x^2 + 2*15 + y^2 = 121

    x^2 + y^2 = 91

    3)

    |x| - 1 = 2x + 1

    a) if   x \geq 0

     |x| = x

     x - 1 = 2x + 1

     x = -2

    but  x \geq 0

    so this is not a solution

    b) if  x < 0

     |x| = -x

     -x - 1 = 2x + 1

     3x = -2

     x = -\frac{2}{3}
    Last edited by josipive; October 28th 2009 at 05:21 AM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: February 4th 2011, 09:39 AM
  2. Replies: 2
    Last Post: December 6th 2010, 04:03 PM
  3. Algebra or Algebra 2 Equation Help Please?
    Posted in the Algebra Forum
    Replies: 4
    Last Post: May 12th 2010, 12:22 PM
  4. Replies: 0
    Last Post: April 24th 2010, 12:37 AM
  5. i need help NOW with my algebra please
    Posted in the Algebra Forum
    Replies: 19
    Last Post: April 17th 2008, 08:08 PM

Search Tags


/mathhelpforum @mathhelpforum