(1²+3²+5²+...+99²)-(2²+4²+6²+...+100²)
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第1个回答 推荐于2021-01-29
1²+3²+5²+...+99²)-(2²+4²+6²+...+100²)
=1²-2²+3²-4²+5²-6²+……+99²-100²
=(1-2)*(1+2)+(3-4)*(3+4)+(5-6)*(5+6)+……+(99-100)*(99+100)
=-3-7-11-……-199
=(-3-199)*50/2
=-5050本回答被提问者采纳
=1²-2²+3²-4²+5²-6²+……+99²-100²
=(1-2)*(1+2)+(3-4)*(3+4)+(5-6)*(5+6)+……+(99-100)*(99+100)
=-3-7-11-……-199
=(-3-199)*50/2
=-5050本回答被提问者采纳