請教請教,5知用咩公式呀,三角?長方?
回答 (2)
2006-12-26 1:54 am
1+2+2+3+3+4+4+5+5..............+49+49+50+50
= 2(1+2+3+4+5..............+49+50)-1
= 2 ((1+50)x50/2) - 1
= 2550 - 1
=2549
= 2(1+2+3+4+5..............+49+50)-1
= 2 ((1+50)x50/2) - 1
= 2550 - 1
=2549
2006-12-26 1:51 am
50*51/2*2-1
=2549
=2549
收錄日期: 2021-04-12 21:59:49
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