Question

If the sum of n terms of an ap is 3n^2+5n find the common difference

Answer 1

Answer:

common difference=6

Step-by-step explanation:

s1=3(1)(^2+5*1=3+5=8

S2=3(2)^2+5*2=12+10=22

s3=3(3)^2+5*3

=27+15=42

Now S2=A1+A2

s3=A1+A2+A3

A3=S3-S2=42-22=20

a=S1=8

A3=a+2d

20=8+2D

2d=12

d=6