Đáp án+Giải thích các bước giải:

 `a)`

`A= 4 8/15 -(2/5- 3 1/3)+|1/2-4/5|`

`=4+8/15-2/5+3 1/3+|5/10-8/10|`

`=4+8/15-2/5+3+1/3+|-3/10|`

`=7+(8/15-2/5+1/3)+3/10`

`=(70/10+3/10)+(8/15-6/15+5/15)`

`=73/10+7/15`

`=(219)/(30)+14/30`

`=(233)/(30)`

Vậy `A=(233)/(30)`

`b)`

`B=-2 2/3- 5/12-|5/6-1 1/3|-(5/12-7/6)`

`=-(2+2/3)-5/12-|5/6-(1+1/3)|-5/12+7/6`

`=-8/3-10/12+7/6-|5/6-4/3|`

`=-8/3-5/6+7/6-|-1/2|`

`=-8/3+1/3-1/2`

`=-7/3-1/2`

`=-14/6-3/6`

`=-17/6`

Vậy `B=-17/6`

`c)`

`C=(-5/12+7/4-3/8)-| 4 1/2- 7 1/3|`

`=(-10/24+42/24-9/24)-|4+1/2-(7+1/3)|`

`=23/24-|(4-7)+(1/2-1/3)|`

`=23/24-|-3+1/6|`

`=23/24-|-18/6+1/6|`

`=23/24-|-17/6|`

`=23/24-17/6`

`=23/24-68/24`

`=-45/24`

`=-15/8`

Vậy `C=-15/8`

`d)`

`D= 2 1/4+ 1 3/5-|1 3/5- 2 7/10|-2 7/10`

`=(2+1/4)+(1+3/5)-|1+3/5-(2+7/10)|-(2+7/10)`

`=2+1/4+1+3/5-2-7/10-|(1-2)+(3/5-7/10)|`

`=1+(1/4+3/5-7/10)-|-1-1/10|`

`=1+(1/4+3/5)-7/10-|-11/10|`

`=1+(5/20+12/20)-7/10-11/10`

`=1+17/20-9/5`

`=20/20+17/20-36/20`

`=1/20`

Vậy `D=1/20`