Giải giúp mình bài này nhé

Đáp án:

 `2,5xx12,5xx8xx0,4`

`=(2,5xx0,4)xx(12,5xx8)`

`=1xx100`

`=100`

___________________

`25xx1,25xx8xx0,4`

`=(25xx0,4)xx(1,25xx8)`

`=10xx10`

`=100`

__________________

`1/2: 0,5- 1/4:0,25+ 1/8: 0,125-1/10:0,1`

`=1/2: 2/10- 1/4: 25/100+ 1/8: 125/1000-1/10: 10/100`

`=1/2: 1/2- 1/4: 1/4+ 1/8: 1/8-1/10: 1/10`

`=1/2 xx 2- 1/4 xx4 + 1/8xx8 -1/10xx 10`

`=2/2-4/4+8/8-10/10`

`=1-1+1-1`

`=0+0`

`=0`