7+14+21+28+……+777+784奥数?
10个回答
展开全部
7+14+21+28+......+707
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
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展开全部
7+14+21+28+......+707
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
展开全部
7+14+21+28+......+707
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
展开全部
7+14+21+28+......+707
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
展开全部
7+14+21+28+......+707
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
=(7+707)X[(707-7)÷7+1]÷2
=714X101÷2
=357X101
=357X100+357X1
=35700+357
=36057
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
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