14/15+34/35+62/63+98/99+142/143+194/195+254/255+322/323+398/399+482/483=?

分类: 作业答案 • 2021-12-19 18:36:39

问题描述：

答

每一项变成1－一个数.如14/15=1-1/15
然后原式＝10-1/15-1/35-1/63-.-1/483
=10-1/(3*5)-1/(5*7)-.-1/(21*23)
=10-1/2(1/3-1/5+1/5-1/7+.+1/21-1/23)
=10-1/2*(20/69)
=680/69