Results 1 to 3 of 3

Math Help - Weird consecutive numbers question...

  1. #1
    Newbie
    Joined
    Feb 2008
    From
    Auckland, NZ
    Posts
    16

    Question Weird consecutive numbers question...

    Take 3 consecutive numbers, e.g. 5,6,7.

    • Square each one.
    • Add the 3 squares.
    • Subtract 2 from the sum.
    • Divide the result by 3.
    • Write down number.


    • Take 3 other consecutive numbers 10, 11, 12 & repeat.


    • Predict answer for 19, 20, 21.


    • Using n, n+1, n+2 simplify and show how this pattern works.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member
    Joined
    Jun 2007
    From
    Cambridge, UK
    Posts
    41
    Hi,

    How far have you got with this question - what part are you looking for help with?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Behold, the power of SARDINES!
    TheEmptySet's Avatar
    Joined
    Feb 2008
    From
    Yuma, AZ, USA
    Posts
    3,764
    Thanks
    78
    Quote Originally Posted by clarebear14 View Post
    [*]Using n, n+1, n+2 simplify and show how this pattern works.[/LIST]
    adding the three numbers we get

    n^2+(n+1)^2+(n+2)^2 \iff n^2+n^2+2n+1+n^2+4n+4

    3n^2+6n+5 Now subtract 2


    3n^2+6n+5-2 = 3n^2+6n+3=3(n^2+2n+1)=3(n+1)^2

    Now divide by 3

    \frac{3(n+1)^2}{3}=(n+1)^2

    So we get the square of of the second #. Yeah
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: September 23rd 2009, 01:04 PM
  2. Replies: 2
    Last Post: April 30th 2009, 07:28 AM
  3. consecutive numbers
    Posted in the Algebra Forum
    Replies: 4
    Last Post: April 27th 2008, 01:38 PM
  4. Consecutive numbers
    Posted in the Math Topics Forum
    Replies: 3
    Last Post: September 24th 2006, 04:57 PM
  5. consecutive numbers
    Posted in the Math Topics Forum
    Replies: 4
    Last Post: July 6th 2006, 03:02 PM

Search Tags


/mathhelpforum @mathhelpforum