Math, asked by rdey20565, 1 year ago

Question number 33
Write the answer correctly.
Answer ?33

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Answers

Answered by drushasangwan
2

Answer:

Step-by-step explanation:

The solution is in pic

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rdey20565: Thanks for your answer
Answered by dhaniharkeerat
2

Let the sum of n terms be given by Sn

so

Sn = 3n²/2+ 5n/2

S1 = 3(1)²/2 + 5(1)/2

= 3/2+5/2 => 4

so 1st term is 4 say 'a'

Now

S2 = 3(2)²/2 + 5(2)/2

= 6+5 => 11

Now a2 = S2 - a1

=> a2 = 11-4 = 7

Now common difference (d)

= a2-a1 => 7-4 = 3

we know

an = a+(n-1) d

so

a25 = 4 + (25-1)(3)

=> a25 = 4 + 24×3 =>4+ 72

so 25th term of the AP is 76.

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