Арифметическая прогрессия

Discussion in 'Болталка' started by Топе, 13 Dec 2011.

Thread Status:
Not open for further replies.
  1. Топе

    Топе Banned

    Joined:
    2 Oct 2010
    Messages:
    70
    Likes Received:
    9
    Reputations:
    2
    Найдите a1 и d арифметической прогрессии, в которой


    a5-a3=-4 ;
    a2*a4=-3

    (система)
     
  2. moodoone

    moodoone Member

    Joined:
    21 Oct 2009
    Messages:
    144
    Likes Received:
    38
    Reputations:
    5
    a1+4d-a1-2d=-4
    2d=-4
    d=-2

    (a1+d)(a1+3d)=-3
    (a1-2)(a1-6)=-3

    a1^2-8a1+15=0
    D=64-60=4
    a11=3
    a12=5

    a1=3
    d=-2

    a1=5
    d=-2
     
  3. Топе

    Топе Banned

    Joined:
    2 Oct 2010
    Messages:
    70
    Likes Received:
    9
    Reputations:
    2
    Спасибо
     
Loading...
Similar Threads - Арифметическая прогрессия
  1. altblitz
    Replies:
    0
    Views:
    993
  2. Deathdreams
    Replies:
    10
    Views:
    1,616
Thread Status:
Not open for further replies.