Math, asked by Sanchari6357, 10 months ago

If last term of ap is 5,3,1,-1 is -41 find the no of terms

Answers

Answered by abhi569
15

Answer:

24

Step-by-step explanation:

In APs nth term is given by a + ( n - 1 )d, where a is the first term and d is the common difference.

Here, let the number of terms be n.

First term = a = 5

Co. di. = d = 3 - 5 = - 2

  ⇒ - 41 = a + ( n - 1 )d

⇒ - 41 = 5 + ( n - 1 )( - 2 )

⇒ - 41 - 5 = ( n - 1 )( - 2 )

⇒ - 46 = ( n - 1 )( - 2 )

⇒ 46 = ( n - 1 )2

⇒ 23 = n - 1

⇒ 23 + 1 = 24 = n

  Hence the required number of term is 24

Answered by Anonymous
5

di. = d = 3 - 5 = - 2

 ⇒ - 41 = a + ( n - 1 )d

⇒ - 41 = 5 + ( n - 1 )( - 2 )

⇒ - 41 - 5 = ( n - 1 )( - 2 )

⇒ - 46 = ( n - 1 )( - 2 )

⇒ 46 = ( n - 1 )2

⇒ 23 = n - 1

⇒ 23 + 1 = 24 = n

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