maths

the first three terms of an a.p are x,2x+1 and 5x-1.find x and the sum of the first 10 terms

  1. 👍 0
  2. 👎 0
  3. 👁 140
  1. 2x-1;3x;5x-2
    5x-2-3x=3x-(2x-1)
    x=3
    S = ½(2a + (n-1)d)n
    5*3-2=13
    3x=9
    13-9=4

    1. 👍 0
    2. 👎 0
  2. 2x+1 - x = 5x-1 - (2x+1)
    find x. Now you know that a=x and d=x+1
    S10 = 10/2 (2a+9d)

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. math

    5. In a geometric sequence, the sum of the first five terms is 44 and the sum of the next five terms is -11/8. Find the common ratio and first term of the series.

  2. maths

    In an arithmatic sequence, sum of 9 terms is 279 and sum of 20 terms is 1280. Find 5th term ? Find 16th term ? Write the sequence.

  3. math

    The sum of the first 20 terms of an arithmetic series is identical to the sum of the first 22 terms. If the common difference is -2, find the first term.

  4. mathematics

    In a geometric progression with terms, the sum of the first and last term is 66 and the product of the second and second last term is 128. Given that the sum of all the terms of this geometric progression is 126, find the number

  1. mathematics

    1} the first term of an AP is 2 and the common difference is 3.Find the sum of the first 11 terms. 2}The 2nd and 5th terms of a GP are -6 and 48 respectively.Find the sum of the first four terms

  2. Maths

    The 2nd, 5th, and 14th term Of an AP are consecutive terms of a GP. Given that the sum of the three terms of the AP is 9, find the A, first term and the common difference of the AP. B common ratio of the GP C sum of the first

  3. maths

    the sum of the first two terms of a GP is 28,but the sum of the third and fourth terms is 252.find the second term of the gp if the seventh term is 5103. please help.

  4. math

    An arithmetic series is such that the 10th term is 40 and the sum of the first 10 terms is 265. Find the sum of the first 20 terms.

  1. Math

    The sum of the first 21 terms of a linear sequence is 28 and the sum of the first 28 terms is 21 . find which term of the sequence is 0 and also the sum of the terms preceeding it

  2. 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

  3. arithmetic

    find the common difference of A.P whose first term is 5 and the sum of its first 4 terms is half the sum of next 4 terms

  4. 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.

You can view more similar questions or ask a new question.