Question

Given that Sn = 1a + (n-1)d1

find the value of Sn if a = 3,n= 10 and
express d in terms of Sn, n and a
2​

Answer 1

d = (sn - 3)/9

Explanation:

Answer 2

Explanation:

Sn = a + (n-1)d

Sn = 3 + (10-1)*d

Sn = 3 + 9d

3 + 9d = Sn

9d = Sn - 3

d = (Sn - 3)/9