Post a New Question

arithmetic

posted by .

the sum of the 4th and 8th terms is 10, and the sum of the 6th and 12th terms is 22. Find the first three terms.

  • arithmetic -

    a + 3d + a + 7d = 10
    2a + 10d = 10
    a + 5d = 5

    a+5d + a+11d = 22
    2a + 16d = 22
    a + 8d = 11

    subtract them
    3d = 6
    d = 2
    back into the first
    a + 5d = 5
    a + 10 = 5
    a = -5

    first 3 terms are -5, -3, -1

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. math

    1) If the sum of the first n terms of a series is Sn where Sn=2n²-n, (a)prove that the series is an AP, stating the first term and the common difference; (b)find the sum of the terms from the 3rd to the 12th inclusive 2) In an AP …
  2. Math

    1) If the sum of the first n terms of a series is Sn where Sn=2n²-n, (a)prove that the series is an AP, stating the first term and the common difference; (b)find the sum of the terms from the 3rd to the 12th inclusive 2) In an AP …
  3. 10th math

    The sum of the 4th and 8th terms of an AP is 24 and the sum of the 6th and 10th terms is 44. Find the first three terms of AP
  4. algebra 2

    An arithmetic progression has 5 terms that have a sum of 200. The sum of the last three terms added to 6 times the sum of the first two terms equals zero. What is the first term?
  5. Geometric

    1) The sum of last three terms of GP having n terms is 1024 time the sume of first 3 terms of GP. If 3rd term is 5. Find the last term. 2) The sum of the first eight terms of a GP is five times the sum of the first four terms. Find …
  6. maths

    the sum of the 4th and 6th terms of an A.P is 42. the sum of the 3rd and 9th terms of the progression is 52. find the first term, the common difference and the sum of the first ten terms of the progression.
  7. Math

    Sum of4th and the 6th terms of an a,p is 42 . While the sum of the 3rd and 9th terms of the same a.p is 52. Find the (a) first term (b)common difference (c) sum of the first ten terms of the progression. Solution
  8. Math

    In an arithmetic series, the sum of the 5th to the 8th terms inclusive is 114, whilst the sum of the 12th to 15th terms inclusive is 198. What is the 21st term?
  9. Day secondary school kataeregi

    The first and last terms of an a.p are 79 and 5 and it's sum is 814 find(a) the number of terms in the a.p(b)the common different between them.(c) the 9th terms is of an a.p is 52, while the 12th terms is 70 find the sum of it's 20th …
  10. Math3c

    1.Find an A.P. such that the sum of the first three terms is one half the sum of the next four terms,the first term being 12. 2.In an A.P.,the sum of the first three terms is 18,and the sum of the squares of these terms is 126.Find …

More Similar Questions

Post a New Question