Giúp mình câu B, C, D vớii ạ

Đáp án`+`Giải thích các bước giải:

`b,`

`B=((-6)/5+6/19-6/23)/(9/5-9/19+9/23)`

`B=((-6)/5-(-6)/19+(-6)/23)/(9. (1/5-1/19+1/23))`

`B=(-6. (1/5-1/19+1/23))/(9. (1/5-1/19+1/23))`

`B=(-6)/9=(-2)/3`

Vậy `C=(-2)/3`

`$\\$

`c,`

`C=(1/6-1/39+1/51)/(1/8-1/52+1/68)`

`C=(4/24-4/156+4/204)/(3/24-3/156+3/204)`

`C=(4. (1/24-1/156+1/204))/(3. (1/24-1/156+1/204))`

`C=4/3`

Vậy `C=4/3`

$\\$

`d,`

`D=(0,75-0,6+3/7+3/13)/(2,75-2,2+11/7+11/13)`

`D=(3/4-3/5+3/7+3/13)/(11/4-11/5+11/7+11/13)`

`D=(3. (1/4-1/5+1/7+1/13))/(11. (1/4-1/5+1/7+1/13))`

`D=3/11`

Vậy `D=3/11`