1/1x3+1/3x5+1/5x7+.1/49x51的简便方法

来源：学生作业帮编辑：拍题作业网作业帮分类：数学作业时间：2024/06/12 13:41:44

1/1x3+1/3x5+1/5x7+.1/49x51
=1/2 ×[2/(1x3)+2/(3x5)+2/(5x7)+.2/(49x51)]
=1/2×[(1-1/3)+(1/3-1/5)+(1/5-1/7)+.+(1/49-1/51)]
=1/2×（1-1/51)
=25/51
再问：能再简单一点吗
再答： 2/1x3=1-1/3 2/3x5=1/3-1/5 2/5x7=1/5-1/7 2/49x51=1/49-1/51 知道这个就行了下面就应该明白了

1+2x3+4x5+6x7+.50x51的和是奇数还是偶数?写出原因 1/1x3+1/3x5+1/5x7+.+1/1997x1999 简便计算. 【分数】1/1x3+1/3x5+1/5x7+…+1/2009x2011要清楚过程的,乘用x代替,用简便方法计算 1/1X3+1/3X5+1/5X7...1/17X19+1/19X21= 1/1x3+1/3x5+1/5x7.1/2009x2010+1/2011x2013 1/1x3+1/3x5+1/5x7+1/7x9+1/9x11=? 计算：1/1x3+1/3x5+1/5x7+...1/2009x2011+1/2011×2013 1/1x3+1/3x5+1/5x7+……+1/99x101 1/1x3+1/3x5+1/5x7+…+1/2011x2013是多少? 1/(1x3)+1/(3x5)+1/(5x7)+.+1/(2011x2013) 等于什么 1/1x3+1/3x5+1/5x7+.+1/2009x2011= 1X3分之1+3X5分之1+5X7分之1+...+2013X2015分之1