Find the value of X, if a 12 the term of AP is X -7, X -2, X +3,...... is 81.also find the sum of 12.
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the question seems incorrect . it should be 12th term
ritikmalik445:
Hn to bosk nikal le
kesi baate kr raha hai saale bc tujhe ans nikalne ke liye kaha hai or tu backchodi maar raha hai beta hua
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sale baap ko gali
Beta km bol sada bolega
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Jitna bhi gand me guda hai na sara nikl jaega ek baari main
Answered by
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Answer:
Step-by-step explanation:
Given 12th is 81
AP.is = x-7 , x-2, x-3.........
Now,
a=x-7
d=(x-2)-(x-7)=5
Then,
12th term =81
a+11d=81
(x-7)+55=81
x=33
Now a = 33-7=26
Sum.of 12 terms is equal to
S12=n/2 (2a+(n-1)d
S12=12/2 (52+(11)5
S12=642.
HOPE IT HELPS U.....
Thanks bro
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