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If Sn=1^2-2^2+3^2-4^2+5^2-6^2+ ,t h e n ...

If `S_n=1^2-2^2+3^2-4^2+5^2-6^2+ ,t h e n` `S_(40)=-820` b. `S_(2n)> S_(2n+2)` c. `S_(51)=1326` d. `S_(2n+1)> S_(2n-1)`

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