1/1*3+1/3*5+1/5*7+...1/97*99
1/1*3+1/3*5+1/5*7+...+1/95*97+1/97*99
1-3+5-7+9.+97-99
-1-3-5-7-9-...-97-99
-1+3-5+7-9.-97+99
计算1-3+5-7+...+97-99
1*1/3+3*1/5+5*1/7+.+97*1/99+99*1/101=
1/(1×3)+1/(3×5)+1/(5×7).+1/(97×99)+1/(99×101)
1/1*3*5+1/3*5*7+1/5*7*9.+1/95*97*99
1/1*3+1/3*5+1/5*7……1/97*99=
1/(1*3)+1/(3*5)+1/(5*7)+----1/(97*99)等于多少?
1/1*3+1/3*5+1/5*7+···+1/97*99=?
1/3*5+1/5*7+1/7*9+……1/97*99