1-1/10+3-1/40+5-1/88+7-1/154+9-1/238+11-1/340
1-1/10+3-1/40+5-1/88+7-1/154+9-1/238+11-1/340
1/10+1/40+1/88+1/154+1/238+1/340=
(1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9+1/10+1/11+1/12+1/13+1/14+1/
(1/3+1/5+1/7+1/9)*(1/5+1/7+1/9+1/11)-(1/3+1/11+1/5+1/7+1/9)*
简算:1/1*3+1/3*5+1/5*7+1/7*9+1/9*11
计算:1/3*5+1/5*7+1/7*9+1/9*11+1/11*13
一道算式题!12/7+5/12-2/154/11+5/9+7/11+1/913/25-1/8-5/258/9-3/8-1
1/1*3+1/5*7+ 1/9*11+.1/(2n-1)(2n+1)
1/3+1/5+1/7+1/9+1/11+1/13+1/15=
1×3/1+3×5/1+5×7/1+7×9/1+9×11/1+11×13/1简便运算
数列2/1+3/1+4/1+5/1+6/1+7/1+8/1+9/1+10/1+11/1……100/1求和
-1,+1/2,-1/3,+1/4,-1/5,+1/6,-1/7,+1/8,-1/9,+1/10,-1/11,.第30个