Question

If the sum of first n terms is 2n+3n square .
Then find the general term

Answer 1

Answer:

6n - 1

Step-by-step explanation:

Sn = 2n + 3n^2

$2n + 3 {n}^{2} \\ s1 = 2(1) + 3 {(1)}^{2} \\ = 2 + 3 = 5 \\ \\ s2 = 2(2) + 3 {(2)}^{2} = 4 + 12 \\ = 16 \\ \\ s3 = 2(3) + 3 {(3)}^{2} \\ = 6 + 27 \\ = 33$

a = 5

a + a + d = 16

5 + 5 + d = 16

d = 16 - 10

d = 6

the general term

an = a + (n-1)d

= 5 + (n-1)6

= 5 + 6n - 6

= 6n - 1

hope you get your answer