Question

1/2x3 + 1/3x4 + 1/4x5 + 1/5x6 ? ( các bạn nêu từng bước giải nhé :3 )

Answer 1

`1/[2xx3]+1/[3xx4]+1/[4xx5]+1/[5xx6]`

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

`=1/2+(-1/3+1/3)+(-1/4+1/4)+(-1/5+1/5)-1/6`

`=1/2-1/6`

`=3/6-1/6`

`=2/6=1/3`