4^2-1/3^2 X 5^2-1/4^2 X 6^2-1/5^2 x~~~~~~~~~~~~~~~~25^2-1/24^2=??
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訪客 (未驗證)

2006-03-09 21:11
是"(4^2-1)/3^2 X (5^2-1)/4^2 X (6^2-1)/5^2 x~~~~~~~~~~~~~~~~(25^2-1)/24^2=??"嗎?

訪客 (未驗證)

2006-03-09 22:45
應該是這樣
原式=(4-1)(4+1)/3^2 X(5-1)(5+1)/4^2 X(6-1)(6+1)/5^2 X...... X(24-1)(24+1)/23^2 X(25-1)(25+1)/24^2
=5/3+6/4+7/5+......+25/23+26/24
=(1+2/3)+(1+2/4)+......+(1+2/23)+(1+2/24)
=22+2(1/3+1/4+1/5+......+1/23+1/24)

數字有點不好算,不知道有沒有更簡單明瞭的式子 :-? :-?

qqwwee2006

2006-03-14 21:38
4-1)(4+1)/3^2 X(5-1)(5+1)/4^2 X(6-1)(6+1)/5^2 X...... X(24-1)(24+1)/23^2 X(25-1)(25+1)/24^2
=5/3+6/4+7/5+......+25/23+26/24
=(1+2/3)+(1+2/4)+......+(1+2/23)+(1+2/24)
=22+2(1/3+1/4+1/5+......+1/23+1/24)

先把它用乘法攻是做好是對了旦我所說的是全部城起來為何第二個等號出現了+法呢!?