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Find the sum of first 10 terms for the series 1×2 + 2×3 + 3×4 + 4×5 |
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Answer» sum=440Step-by-step EXPLANATION: 1×2 + 2×3 + 3×4 + 4×5 nth TERM of series=N(n+1)=n²+nSum of n terms=∑n²+ ∑n=n(n+1)(2n+1)/6 +n(n+1)/2Putting n=10sum=10*11*21/6+10*11/2=385+55=440 |
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