1/3 1 1 13/17 17/33 ( ) 找规律填数 A 21/34 B21/65 C 17/53 D 1

1,3,8,13,17 1/3 1 1 13/17 17/33 ( ) 找规律填数 A 21/34 B21/65 C 17/53 D 1 1/3,1/5,-5/9,13/17,-29/33,61/65 通项公式 1/(11*13*15)+1/(13*15*17)+.+1/(29*31*33)=如何解答 数奥难题：1/11×13×15+1/13×15×17+.1/29×31×33 1/(11*13*15)+1/(13*15*17)+.+1/(29*31*33)= 计算1/11*13*15 +1/13*15*17 +1/15*17*19+.29*31*33=?1/11*13*15 +1/13*15*17 +1/15*17*19+.29*31*33=?1/11*13*15 +1/13*15*17 +1/15*17*19+.1/29*31*33=? 初一奥数题1*1/5+5*1/9+9*1/13+13*1/17+...+33*1/37 34×（1/17+1/13）×13 1/17*16/33+16/17简便计算 1-1-11+3+3-1+8-99+5-3-2-1-0+33+22+17 17,18,14,8,3,15,13,26,5,26,7,24,11,1,30,20,20,27,3,15,26,3,9,8,21,29,33,18,13,27,（ 19,23,17,21,15,4,16,15,6,17,3,5,10,15,33,26,17,7,15,13,32,1,12,13,18,26,6,20,12,12（ 13/17-1/34+1/3= 简便计算 1/11*13*15+1/13*15*17+.．．．+1/29*31*33咋解请问这题咋解? 1/11×13×15+1/13×15×17+······+1/29×31×33 1/17+2/17+3/17+...+15/17+16/17+1+16/17+15/17+...+3/17+2/17+1/17= (78/1+17/1)*13+4/17 简便计算 (1/17+1/15)×4+13÷17简便计算