Đáp án:

 Bài 1: Thực hiện phép tính:

a, `25% - 1 1/2 + 0,5 . 12/5`

 `=1/4 - 3/2 +1/2 . 12/5`

 `=1/4 - 6/4 + 6/5`

 `= -5/4 + 6/5 = -25/20 + 24/20 = -1/20`

b,|$\frac{-7}{9}|$ + ($\frac{-1}{3})²$  - $(-2016)^{0}$ 

  `=7/9 + 1/9 - 1`

  `=8/9 - 1 = 8/9 - 9/9 = -1/9`

c,`(-3/11 : 5/9 + -8/11 : 5/9) . (|-5|)/3`

`=(-3/11 . 9/5 + -8/11 . 9/5) . 5/3`

`=[ 9/5 . (-3/11 + -8/11)] . 5/3`

`=[ 9/5 . (-1) ] . 5/3`

`=-9/5 . 5/3 = -3`

`text{ @toanisthebest}`

Đáp án:

`a,`

`25% - 1 1/2 + 0,5 × 12/5`

`= 25% - 3/2 + 6/5`

`= 1/4 - 3/2 + 6/5`

`= 5/20 - 30/20 + 24/20`

`= (5 - 30 + 24)/20`

`= (-1)/20`

$\\$

`b,`

`|-7/9| + (-1/3)^2 - (-2016)^0`

`= 7/9 + 1/9- 1`

`= 7/9 + 1/9 - 9/9`

`= (7 + 1 - 9)/9`

`= (-1)/9`

$\\$

`c,`

`( (-3)/11 ÷ 5/9 + (-8)/11 ÷ 5/9) × (|-5|)/3`

`= [(-3)/11 × 9/5 + (-8)/11 × 9/5] × 5/3`

`= [9/5 × ( (-3)/11 + (-8)/11)] × 5/3`

`= [9/5 × (-1)] × 5/3`

`= (-9)/5 ×5/3`

`= -3`