the sum of n, 2n,3n terms of A P are s1, s2, s3 respectively prove that s3=3(s2-s1) - Maths - Sequences and Series

Question

the sum of n, 2n,3n terms of A P are s1, s2, s3 respectively
prove that s3=3(s2-s1)

Shridhar Kaushik · Accepted Answer

Let the first term of the A P be a and the common difference be d According the question,

We have to prove that S3 = 3 ( S2 â€“ S1) R H S = 3 (S2 â€“ S1)

= S3 = L H S â‡’ S3 = 3 ( S2 â€“ S1)

the sum of n, 2n,3n terms of A.P. are s1, s2, s3 respectively. prove that s3=3(s2-s1)