1/14*15+1/15*16+1/16*17+1/17*18
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/20 21:38:35
![1/14*15+1/15*16+1/16*17+1/17*18](/uploads/image/z/2699826-42-6.jpg?t=1%2F14%2A15%2B1%2F15%2A16%2B1%2F16%2A17%2B1%2F17%2A18)
1/14*15+1/15*16+1/16*17+1/17*18
1/14*15+1/15*16+1/16*17+1/17*18
1/14*15+1/15*16+1/16*17+1/17*18
1/(14*15)+1/(15*16)+1/(16*17)+1/(17*18)
=1/14-1/15+1/15-1/16+1/16-1/17+1/17-1/18
=1/14-1/18
=1/63