1又1/2-1/12-1/20-1/30-1/42
来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/19 12:32:41
1又1/2-1/12-1/20-1/30-1/421又1/2-1/12-1/20-1/30-1/421又1/2-1/12-1/20-1/30-1/421又1/2-1/2+1/3-1/3+1/4-1/5
1又1/2-1/12-1/20-1/30-1/42
1又1/2-1/12-1/20-1/30-1/42
1又1/2-1/12-1/20-1/30-1/42
1又1/2-1/2+1/3-1/3+1/4-1/5+1/5-1/6+1/6-1/7
1-1/7
=6/7
要答案还是要简便算法呀？