Question

solve 2nd one justify and explain​

Answer 1

Sn=3n^2+5n

d=coefficient of n square*2

d=3*2

d=6

Answer 2

Sn=3n2+5n

S(1)=3(1)2+5(1)

3+5=8

S(2)=3(2)2+5(2)

12+10

22

S(3)=3(3)2+5(3)

27+15

42

A1=8

A2=S3-S2

42-22

20

d=A2-A1

20-8

12

HOPE this helps u.....