Question

Explain the problem with same steps given in the solution below the question!​
with final result!!!

Answer 1

Answer:

Given

Sn = 3n² + 5n .....1

Sn-1 means, sum of second last

term

by putting the n-1 in place of n of eq1

Sn-1 = 3n² - n - 2

there's a formula

a ñ = Sn - Sn-1

a ñ = 3n²+ 5n-( 3n²-n-2)

Answer 2

Answer:

refers to the attachment