The no of terms in an AP is 40 and the last is -54,given that the sum of the 15 terms added to the sum of the first 30 terms is zero.calculate(1)the first term and common difference.(2)sum of progression

2 answers

a+39d = -54

S15 = 15/2 (2a+14d)
S30 = 30/2 (2a+29d)
So, 15/2 (2a+14d) + 30/2 (2a+29d) = 0
or, a+12d = 0

Now you have two equations, and you can find a and d, and then the sum S40.
Thanks we'll calculated
Similar Questions
  1. Identify the terms as like or unlike terms.10xy, −15xy 10 𝑥 𝑦 , − 15 𝑥 𝑦 (1 point) Responses The terms are like
    1. answers icon 1 answer
  2. Identify the terms as like or unlike terms.10xy, −15xy (1 point) Responses The terms are like terms. The terms are like terms.
    1. answers icon 1 answer
    1. answers icon 1 answer
  3. Use the table to answer the question.Terms 1 10 20 Terms 2 20 40 Terms 3 30 60 Terms 4 40 80 Divide to prove each ratio is
    1. answers icon 3 answers
more similar questions