1+3+5......+49+51+49+......+5+3+1
列式計算
正方形數教!急
2007-03-25 3:24 am
回答 (7)
2007-03-25 4:25 am
✔ 最佳答案
1+3+5......+49+51+49+......+5+3+1=(1+3+5......+49)*2 + 51
={[(1+49)/2]^2}*2+51
=[(50/2)^2]*2+51
=(25*25)*2+51
=625*2+51
=1250+51
=1301
2007-03-26 6:50 am
1+3+5......+49+51+49+......+5+3+1
=2(1+3+5......+49)+51
=2*25(1+49)/2 +51
=1250+51
=1301
====
=2(1+3+5......+49)+51
=2*25(1+49)/2 +51
=1250+51
=1301
====
2007-03-26 5:06 am
連續奇數總和=(初項+末項)/2 的2次方
1+3+5......+49+51+49+......+5+3+1
=(1+3+5+......+51)+(49+......+5+3+1)
=(1+51)/2 的2次方+(49+1)/2 的2次方
=26^2+25^2
=1301
1+3+5......+49+51+49+......+5+3+1
=(1+3+5+......+51)+(49+......+5+3+1)
=(1+51)/2 的2次方+(49+1)/2 的2次方
=26^2+25^2
=1301
2007-03-25 4:03 am
ans 係 1352 唔記得點計啦!!
2007-03-25 3:55 am
1+3+5......+49+51+49+......+5+3+1
=51*51
=2601
答案係2601
2007-03-24 20:13:38 補充：
計錯左呀,1 3 5...... 49 51 49 ...... 5 3 1=(1 51)/2*(1 51)=1352
2007-03-24 20:14:00 補充：
計錯左呀,1 3 5...... 49 51 49 ...... 5 3 1=(1 51)/2*(1 51)=1352
=51*51
=2601
答案係2601
2007-03-24 20:13:38 補充：
計錯左呀,1 3 5...... 49 51 49 ...... 5 3 1=(1 51)/2*(1 51)=1352
2007-03-24 20:14:00 補充：
計錯左呀,1 3 5...... 49 51 49 ...... 5 3 1=(1 51)/2*(1 51)=1352
2007-03-25 3:35 am
1+3+5+7+9......+49+51=x
x+1+3+5+7+9......+49+51=x
=x+x
=y
x+1+3+5+7+9......+49+51=x
=x+x
=y
收錄日期: 2021-04-13 00:13:45
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https://hk.answers.yahoo.com/question/index?qid=20070324000051KK03988