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Find n and Sn of a = 5 , d=3 An=50. |
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Answer» First apply the formula an=a+(n-1)dan=50, a=5 ,d=3.50=5+(n-1)350-5=(n-1)345=(n-1)345÷3=(n-1)15=(n-1)15+1=n16=nNow,apply Sn=n/2 (2a+(n-1)dSn=16/2 (2×5+(16-1)3Sn=8 (10+45)Sn=8×55Sn=440Therefore, n=16 and Sn=440☺☺ N=60 Sn= 440 an=a+(n_1)d Firstly apply the formula an =a+(n-1) d and then apply the formula to find sum that is sum equal to n/2(2a+(n-1)d) Sorry sorry n= 16 and sn=440 N=12 and sn = 258 n=16, and Sn= 440 |
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