Question

Find the term for ap 9,12,15,18,.....Which is 39 more than its 36th term

Answer 1

Hey there !!


➡Given :-

→ a$\tiny 1$ = 9 .

→ a$\tiny 2$ = 12 .

→ Then, d = a$\tiny 2$ - a$\tiny 1$

=> d = 12 - 9 = 3 .


➡ To find :-

→ n term which is 39 more than its 36th term .


➡ Solution :-

Here a = 9 and d = 3.

•°• 36th term is given by

=> a$\tiny 36$ = a + ( 36 - 1 )d .

=> a$\tiny 36$ = 9 + 35(3) .

=> a$\tiny 36$ = 9 + 105.

°•° a$\tiny 36$ = 114.


•°• Required term = ( 114 + 39 ) = 153.

Let it be nth term . Then,

°•° a$\tiny n$ = a + ( n - 1 )d.

=> 153 = 9 + ( n - 1 )3.

=> 153 - 9 = 3n - 3.

=> 144 = 3n - 3.

=> 144 + 3 = 3n.

=> 3n = 147.

=> n = 147/3 .

•°• n = 49.


✔✔ Hence, 49th term is the required term.✅✅

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THANKS


#BeBrainly.