Đáp án+Giải thích các bước giải:

`a,

`(-2,4 + 1/3 ) : 3 1/10 + 75% : 1 1/2`

`=((-24)/10 + 1/3) : 31/10 + 3/4 : 3/2`

`=((-72)/30 + 10/30) : 31/10 + 3/4 : 3/2`

`=(-62)/30 : 31/10 + 3/4 : 3/2`

`=(-62)/30 . 10/31 + 3/4 : 3/2`

`=(-2)/3 . 1/1 + 3/4 : 3/2`

`=(-2)/3 . 1 + 3/4 : 3/2`

`=(-2)/3 + 3/4 . 2/3`

`=(-2)/3 + 1/2 . 1/1`

`= (-2)/3 + 1/2`

`= (-4)/6 + 3/6`

`=(-1)/6`

`b,`

`1,25:15/20+(25%-5/6):4\frac{2}{3}`

`=1\frac{1}{4}:3/4+(25/100-5/6):14/3`

`=5/4.(4)/3+(1/4-5/6).(3)/14`

`=5/3+(3/12-10/12).(3)/14`

`=5/3-7/12.(3)/14`

`=5/3-1/8`

`=40/24-3/24`

`=37/24`

`c,`

`(-2,5+3 1/2):75%-(1/2-1/6)`

`=(-5/2+7/2):75/100-(3/6-1/6)`

`=2/2:3/4-2/6`

`=1:3/4-1/3`

`=4/3-1/3`

`=3/3`

`=1`