题目有没有漏掉什么呢?
如果题目是:
2/11×13+2/13×15+2/15×17+2/17×19
用列项法
2/11×13+2/13×15+2/15×17+2/17×19
=2/11-2/13+2/13-2/15+2/15-2/17+2/17-2/19
=2/11-2/19
=2(19-11)/11×19
=16/209
题目有没有漏掉什么呢?
如果题目是:
2/11×13+2/13×15+2/15×17+2/17×19
用列项法
2/11×13+2/13×15+2/15×17+2/17×19
=2/11-2/13+2/13-2/15+2/15-2/17+2/17-2/19
=2/11-2/19
=2(19-11)/11×19
=16/209