Đáp án:
`8/9-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2=0`
Giải thích các bước giải:
`8/9-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2`
`=8/9-1/2-1/6-1/12-1/20-1/30-1/42-1/56-1/72`
`=8/9-(1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72)`
`=8/9-(1/1.2+1/2.3+1/3.4+1/4.5+1/5.6+1/6.7+1/7.8+1/8.9)`
`=8/9-(1/1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9)`
`=8/9-(1/1-1/9)`
`=8/9-1/1+1/9`
`=(8/9+1/9)-1`
`=9/9-1`
`=1-1`
`=0`
