If a= 1+3+5+7+9+11+13+..............+99
b=2+4+6+8+10+12+14+16+18......................+98
a-b=?
MATHS
2008-04-18 1:53 am
回答 (3)
2008-04-22 2:14 am
a - b = ( 1 ＋ 3 ＋ 5 ＋ 7 ＋ ... ＋99) - ( 2 ＋ 4 ＋ 6 ＋ ... ＋ 98 )
= 1 + ( 3 - 2 ) + ( 5 - 4 ) + ( 7 - 6 ) + ... + (99 - 98 )
= 1 + 1 + 1 + 1 + ... + 1
= 1 + 49
= 50
= 1 + ( 3 - 2 ) + ( 5 - 4 ) + ( 7 - 6 ) + ... + (99 - 98 )
= 1 + 1 + 1 + 1 + ... + 1
= 1 + 49
= 50
參考: me
收錄日期: 2021-04-13 15:27:07
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https://hk.answers.yahoo.com/question/index?qid=20080417000051KK01621