Question: If the sum of the first $n$ terms of a series be $5 n ^ { 2 } + 2 n$ , then its second term is...

Question

If the sum of the first $n$ terms of a series be $5 n ^ { 2 } + 2 n$ , then its second term is .

Answer 1

$T _ { 2 } = S _ { 2 } - S _ { 1 }$

= $5 ( 2 ) ^ { 2 } + 2 ( 2 ) - \left\{ 5 ( 1 ) ^ { 2 } + 2 ( 1 ) \right\} = 24 - 7 = 17$ .

Question: If the sum of the first \(n\) terms of a series be \(5 n ^ { 2 } + 2 n\) , then its second term is...