1⼀2+1⼀6+1⼀12……+1⼀90=Ab,Ab为最简分数,求a+b是多少?

2025-02-01 07:54:05
推荐回答(1个)
回答1:

1/2+1/6+1/12……+1/90
=1/1*2+ 1/2*3+1/3*4+...+1/9*10
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+...+1/9-1/10
=9/10
所以a+b=9+10=19
望采纳,谢谢