find the sum of first 15 multiles of 9
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Answered by
1
15/2*(9 +135) , 15/2*144,15*72=1080
Answered by
3
the first multiples of 9 are 9 ,18,27, .......... to 15terms
here a= 9, d = 9, n = 15
we know that
sN = n/2*2a+(n-1)d
= 15/2 (2*9)+(15-1)9
= 15/2 *18 + (126)
= 15*9 + 126
= 135 + 126
= 261
therefore
S15 = 261
here a= 9, d = 9, n = 15
we know that
sN = n/2*2a+(n-1)d
= 15/2 (2*9)+(15-1)9
= 15/2 *18 + (126)
= 15*9 + 126
= 135 + 126
= 261
therefore
S15 = 261
akash6339:
wrong ans wer
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