SOLUTION: find the sum when N=20 ,A=2 and D=5 for S=N/2(2a+(N-1)d

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Question 843062: find the sum when N=20 ,A=2 and D=5 for S=N/2(2a+(N-1)d
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

N=20 ,A=2 and D=5

+S=%28N%2F2%29%282a%2B%28N-1%29d%29

 S=20/2(2•2 +(19)5)= 3800

 S=10(99)= 990