Question

given a = 8 , an= 62 , Sn= 210
find - n and d...​

Answer 1

Step-by-step explanation:

n = 6 and I am not conform about d I hope it help u. And I like to make u as my friend

Answer 2

$\huge\bigstar\purple{\boxed{Answer}}$

Given: a = 8 , an= 62 , Sn= 210

To find: n and d

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$\longrightarrow{a_n = a + (n-1)d}</p><p>$

$\longrightarrow{62 = 8 + (n-1) d}$

$\longrightarrow{54 = (n-1) d ---(eq.1)}$

For finding n:-

$\longrightarrow{S_n = \frac{n}{2}[2a +( n - 1) d]}$

$\longrightarrow{210 = \frac{n}{2}[16 +( n - 1) d]}$

$\longrightarrow{420 = {n}[16 + 54]}$

$\longrightarrow{ \boxed {n = 6}}$

For finding d:-

By putting n=6 in eq(1) we get

$\longrightarrow{54 = (6 - 1)d}$

$\longrightarrow{ \boxed{d = \frac{54}{5} }}$