a,-17/30-11/-15+-7/12 b,-5/9+5/9:(1 2/3-2 1/12) c,-7/25.11/13+-7/25.2/13-18/25

Đáp án + Giải thích các bước giải:

a)

`(-17)/30-11/(-15)+(-7)/12`

`=(-34)/60+44/60-35/60`

`=-5/12`

b)

`(-5)/9+5/9:(1 2/3-2 1/12)`

`=(-5)/9+5/9:(1 2/3-2 1/12)`

`=(-5)/9+5/9:(5/3-25/12)`

`=(-5)/9+5/9:(20/12-25/12)`

`=(-5)/9+5/9:(-5)/12`

`=(-5)/9+5/9. (-12)/5`

`=(-5)/9+(-4)/3`

`=(-5)/9+(-12)/9`

`=(-17)/9`

c)

`(-7)/25. 11/13+(-7)/25. 2/13-18/25`

`=(-7)/25.(11/13+2/13)-18/25`

`=(-7)/25.1-18/25`

`=(-7)/25-18/25`

`=-1`