1X3|1+3X5|1+5X7|1+……97|1X99
问题描述:
1X3|1+3X5|1+5X7|1+……97|1X99
答
1/1*3+1/3*5+.1/97*99
=1/2(1-1/3+1/3-1/5+,1/97-1/99)
=1/2(1-1/99)
=49/99