Question

Find the sum of 36 terms of series whose nth term is 5n+4 ?

please answer this question correctly I will mark you brain list and give thanks to you and dont post wrong answers...​

Answer 1

HELLO FRIEND SO HERE IS THE CORRECT ANSWER

Tn = 5n + 4

T1 = 9

T2 = 14

T3 = 19

SO THE A.P. IS 9 , 14 , 19

SO A = 9

D = 5

N = 36

NOW SUM OF THE 36 TERMS IS

Sn= n/2 [ 2a + (n-1)d]

S36 = 36 /2 [ 2× 9 + 35 × 5 ]

= 18 ( 18 + 175 )

= 18 × 193

= 3474 ANSWER

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Answer 2

Step-by-step explanation:

S36 = 18 (2a + 35 .d). ... (1)

t36 = 5 x36 + 4 = 184 = a + 35d ,

a = 184 - 35d .... (2)

t35 = 5 x 35 + 4 = 179

C.D = 184 - 179 = 5 = d

from 1 nd 2

18 (2(184-35d) + 35d) = S36

18( 368 - 35d ) = S36

6624 -18 x 35(5) = S36

6624 - 3150 = S36

S36 = 3474