Question

if Sn' the sum of first n terms of an A.P is given by Sn = 5n2 + 3n then find its nth term

Answer 1

hope it helped you.

Answer 2

Answer:

$n^{th}\: term =a_{n}=10n-2$

Step-by-step explanation:

$Given \: Sum\:of \: first\\n\:terms \:of \:an\:A.P\:is \\</p><p>S_{n}=5n^{2}+3n$

$n^{th}\: term =a_{n}\\=S_{n}-S_{n-1}$

$=5n^{2}+3n-[5(n-1)^{2}+3(n-1)]$

$=5n^{2}+3n-[5(n^{2}-2n+1)+3n-3]$

$=5n^{2}+3n-5n^{2}+10n-5-3n+3$

$=10n-2$

Therefore,

$n^{th}\: term =a_{n}=10n-2$

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