Question

The sum of first n terms of
A. P is 3n2 + Zn. Find is nth term and the series
​

Answer 1

Answer:

12345678901234567890

Answer 2

Step-by-step explanation:

s

n

=3n

2

+6n

s

n−1

=3(n−1)

2

+6(n−1)

s

n−1

=3(n

2

−2n+1)+6n−6

s

n−1

=3(n

2

−2n+1)+6n−6

s

n−1

=3n

2

−6n+3+6n−6

s

n−1

=3n

2

−3

t

n

=s

n

−s

n−1

t

n

=3n

2

+6n−3n

2

+3

t

n

=6n+3

Answer By

Topp