एका अंकगणितीय श्रेढीचे 9 वे पद 18 आहे 4 थ्या व 7 व्या पदांची बेरीज 24 आहे. तर ती श्रेढी काढा
Answers
Given : एका अंकगणितीय श्रेढीचे 9 वे पद 18 आहे 4 थ्या व 7 व्या पदांची बेरीज 24 आहे.
The 9th term of an arithmetic series is 18 and the sum of the 4th and 7th terms is 24
To Find : श्रेढी
Series
Solution:
AP is
a , a + d , a + 2d , .. .. .. ..
aₙ = a + (n - 1)d
Sₙ = (n/2)(2a + (n-1)d)
a₉ = a + 8d = 18
a₄ = a + 3d
a₇ = a + 6d
a₄ + a₇ = 24
=> a + 3d + a + 6d = 24
=> 2a + 9d = 24
a + 8d = 18
2a + 9d = 24
=> 7d = 12
=> d = 12/7
a + 8(12/7) = 18
=> a = 30/7
Series is
30/7 , 42/7 , 54/7 , 66/7 , 78/7 , 90/7 , 102/7 , 114/7 , 126/7 ...
=> 30/7 , 6 , 54/7 , 66/7 , 78/7 , 90/7 , 102/7 , 114/7 , 18 ...
Learn More :
How to derive sum of n terms of an A.P? - Brainly.in
brainly.in/question/7849150
In an A.P. 1st term is 1 and the last term is 20. The sum of all terms is ...
brainly.in/question/4331475
find the sum of AP a1, a2, a3, ....a30. Given that a1 + a7 + a10 + a21 ...
brainly.in/question/14618265
Answer:
a , a + d , a + 2d , .. .. .. ..
aₙ = a + (n - 1)d
Sₙ = (n/2)(2a + (n-1)d)
a₉ = a + 8d = 18
a₄ = a + 3d
a₇ = a + 6d
a₄ + a₇ = 24
=> a + 3d + a + 6d = 24
=> 2a + 9d = 24
a + 8d = 18
2a + 9d = 24
=> 7d = 12
=> d = 12/7
a + 8(12/7) = 18
=> a = 30/7
Step-by-step explanation: