2+4+6+8+10+······+100=?

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2+4+6+8+10+······+100=?

2+4+6+8+10+······+100=?
2+4+6+8+10+······+100=?

2+4+6+8+10+······+100=?
255

255

有公式的,等差数列的公式
等差数列的通项公式为:an=a1+(n-1)d
(1)前n项和公式为:Sn=na1+n(n-1)d/2或Sn=n(a1+an)/2 注意: 以上n均属于正整数。

希望采纳!

2+4+6+8+10+······+100=2(1+2+3+....50)=2(1+50)*25=2550

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