Question

1f the sum of n terms of an A.P. is Sn = 3n² + 5n. Write its common difference.

Answer 1

Step-by-step explanation:

steps are given in the clip

Answer 2

Common difference = 4

Step-by-step explanation:

Given: sum of n terms of an A.P. is Sn = 3n² + 5n

Find: common difference

Solution:

Sn = 3n² + 5n

s1 = a = 3(1) +5 = 9

s2 = 3(4) + 5(2) = 22

a2 = S2 - S1 = 22-9 = 13

d = a2 -a1 = 13 - 9 = +4

Common difference = 4