作业帮1001+1003+1005+······+2009+2011的和是多少?
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1001+1003+1005+······+2009+2011的和是多少?
1001+1003+1005+······+2009+2011的和是多少?
1001+1003+1005+······+2009+2011的和是多少?
首先算项数：（2011-1001）/2+1=506
和为：（1001+2011）*506/2=762036
这要用到高中的等差数列的知识，1001为首项，d是2，S=a1*n+d*n*(n-1)/2,n=506，所以S=1001*506+2*506*505/2=得数你自己算好啦
1001+1003+1005+······+2009+2011的和是多少?
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