1/2+1/6+1/12+1/20+1/30怎么做?

1/2+1/6+1/12+1/20+1/30怎么做?
1/2+1/6+1/12+1/20+1/30怎么做?

1/2+1/6+1/12+1/20+1/30怎么做?
"1/2+1/6+1/12+1/20+1/30

从后往前作补充：或者化为分母60
满意请采纳。

先通分啊...

=1/1×2+1/2×3+1/3×4+1/4×5+1/5×6
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6
=1-1/6
=5/6