Đáp án`+`Giải thích các bước giải`:`

`14)`

`15/11-(6/5-7/11)+26/5`

`=15/11-6/5+7/11+26/5`

`=(15/11+7/11)+(-6/5+26/5)`

`=2+4`

`=6`

`18)`

`23 1/4 * 7/5-13 1/4 : 5/7`

`=23 1/4 * 7/5-13/ 14 * 7/5`

`=7/5 (23 1/4-13 1/4)`

`=7/5 (23+1/4-13-1/4)`

`=7/5 * 10`

`=14`

 `19)`

`(5/4-2/3) * 2023/2024+(3/4-3/5) * 2023/2024`

`=(15/12-8/12) * 2023/2024 +(15/20-12/20) * 2023/2024`

`=7/12 * 2023/2024+3/20 * 2023/2024`

`=2023/2024 (7/12+3/20)`

`=2023/2024 * 11/15`

`=2023/2760`

`20)`

`5/14 * 12 1/2-5/14 * 5 1/2`

`=5/14 (12 1/2-5 1/2)`

`=5/14 (12+1/2-5-1/2)`

`=5/14 * 7`

`=5/2`

`21)`

`(1/4-2/5) : 3/8+(3/4-8/5) : 3/8`

`=(5/20-8/20) : 3/8+(15/20-32/20) : 3/8`

`=(-3/20) : 3/8+(-17/20) : 3/8`

`=[(-3/20)+(-17/20)] : 3/8`

`=(-1) * 8/3`

`=-8/3`

`22)`

`3/8 : (7/22-2/11)+3/8 : (2/5-1/10)`

`=3/8 : (7/22-4/22)+3/8 : (4/10-1/10)`

`=3/8 : 3/22+3/8 : 3/10`

`=3/8 * 22/3+3/8 * 10/3`

`=3/8 (22/3+10/3)`

`=3/8 * 32/3`

`=4`

`@yue`