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標題:

5+6+7+8+9+10........+111 = ?

發問:

5+6+7+8+9+10........+111 = ?

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最佳解答:

=(1+2+3+4+5......+111)-(1+2+3+4) =(1+111)*111/2-(1+4)*4/2 =56*111-5*2 =6216-10 =6116 2006-10-21 14:36:02 補充: 6216-10=6206sorry!

其他解答:

5+6+7+8+9+10........+111 =(5+111)x107/2 ←(頭項+尾項x項數)/2 =6206|||||(5+111)*(111-4) ——————— 2 =116*107 ———— 2 =58*107 =6206 公式:(頭項+尾項)*項數/2|||||1+2+3+4+........+100=5050 111-100=11 1+2+3+4=10 11-10=1 5050+1=5051 lo... 我都不知對不對家! 2006-10-21 10:18:37 補充: 有錯1+2+3+4+........+100=5050101+ 102+ 103+ 104.........+ 111=11661+ 2+ 3+ 4=101166-10 =11565050+ 1156=6206 !!!!!!!!!!!!!!!!!這個絕對正確 !!!!!!!!!|||||111-5=53 (111+5)*53 =6148 2006-10-20 23:01:58 補充: 111-5=106106/2=53(111+5)*53=6148|||||[(5+111)x(111-1-2-3-4)]/2 =5858 2006-10-20 23:06:32 補充: sorryI forget somethingthe real sum is: [(5 111)x(111-5)]/2=[116x106]/2=12296/2=6148|||||5+6+7+8+9+10........+111 =(5+111)x107/2 =6206|||||你可以試下 (首項 + 末項) x 項數 / 2 = (5 + 111) x ( 111 - 5 ) / 2 = ( 116 ) x ( 106 ) / 2 = 6148 2006-10-20 22:42:39 補充: sori我計錯左項數項數 = 111 - 4 = 107so the answer is(首項 末項) x 項數 / 2= (5 111) x ( 111 - 4 ) / 2= ( 116 ) x ( 107 ) / 2= 6206|||||You can your teacher ?...or read Maths book? 2006-10-20 22:36:15 補充: Am I right...!!! 相信我 ...|||||[111*(111+1)]/ 2 - [4*(4+1) ]/ 2 =6216-10 =6206
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