Adv
deepaksoni
  • 0
Guru

Question 1. Find the sum of the following arithmetic progressions(v) a + b, a – b, a – 3b, ….. to 22 terms

  • 0

This is the basic and conceptual question from Chapter name- Arithmetic Progression
Chapter number- 9
Exercise 9.6

In this question we have been given an arithmetic progression. And we have to find its sum upto 22 terms

CBSE DHANPAT RAI publications
Class:- 10th
Solutions of CBSE Mathematics
Question 1( v)

Share

1 Answer

  1. Given A.P. has first term(a) = a + b,

    Common difference(d) = (a – b) – (a + b) = -2b

    and number of terms(n) = 22

    So, Sum of A.P. = S22 = n[2a + (n – 1)d] / 2

    = 22[2(a + b) + (22 – 1)(-2b)]/2

    = 11{2(a + b) – 22b)

    = 11(2a – 40b) = 22a – 440b

    Hence, the sum of the first 22 terms of A.P. is 22a – 440b.

    • 0
Leave an answer

Leave an answer

Browse

Choose from here the video type.

Put Video ID here: https://www.youtube.com/watch?v=sdUUx5FdySs Ex: "sdUUx5FdySs".

Captcha Click on image to update the captcha.

Related Questions