Respuesta :
Given :-
- -13,-2,9,20,31 . . . . .
To find :-
- which term in this sequence is 306 .
Solution :-
Common difference ,
- d = 31 - 20
- d = 11
As we know that ,
- Tⁿ = a + (n-1)d
- 306 = -13 + (n-1)11
- 306+13 = (n-1)11
- 319/11 = n-1
- 29 = n -1
- n = 30
Answer:
30th
Step-by-step explanation:
There is a common difference between consecutive terms, that is
- 2 - (- 13) = 9 - (- 2) = 20 - 9 = 31 - 20 = 11
This indicates the sequence is arithmetic with nth term
[tex]a_{n}[/tex] = a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = - 13 and d = 11 , then
[tex]a_{n}[/tex] = - 13 + 11(n - 1) = - 13 + 11n - 11 = 11n - 24 ← equate to 306
11n - 24 = 306 ( add 24 to both sides )
11n = 330 ( divide both sides by 11 )
n = 30
The 30th term is 306