2/15+2/35+2/63+.+2/323=

来源：学生作业帮编辑：大师作文网作业帮分类：数学作业时间：2024/11/13 17:24:19

2/15+2/35+2/63+.+2/323
=1/3-1/5+1/5-1/7+1/7-1/9+.+1/15-1/17+1/17-1/19
=1/3-1/19
=(19-3)/3*19
=16/57

3Q,怎么简便2/3+2/15+2/35+2/63+2/99+2/143+2/195+2/255+2/323+2/399 简算题 3/2+15/2+35/2+63/2+99/2+143/2=? 2/3+2/15+2/35+2/63+2/99+2/143=? 2/3+2/15+2/35+2/63+2/99 2/15+2/35+2/63+2/99+2/143 2/3+2/15+2/35+2/63+2/99=? 20-2/3-2/15-2/35-2/63-2/99=? 2/3+2/15+2/35+2/63+2/99=用简便方法 20-2/3-2/15-2/35-2/63-2/99= 3/2+15/2+35/2+63/2+99/2=? 选择合适的计算方式2 2 2 2 2-- + --- + --- + --- + ---- = 3 15 35 63 9 8-2/3-2/15-2/35-2/63-2/99-2/143-2/195-2/255=