Câu 9 (2,5 điểm). Thưc̣ hiêṇ phép tính (tính hơp̣ lí nếu có): a) $\frac{5}{12}$ - $\frac{1}{5}$ b) 6.(-$\frac{1}{3}$)² - $\frac{1}{9}$ c) $(\frac{1}{5})^{5}$ : $(\frac{1}{5})^{3}$ - $(\frac{-1}{3})^{3}$ : $(\frac{-1}{3})^{2}$ d) (1 - $\frac{2}{3}$ + $\frac{1}{2}$) - (2 + $\frac{1}{3}$ - 1,5)

`K`

Câu `9:`

`1, 5/12 -1/5`

`=25/60 - 12/60`

`=13/60`

`2, 6 . (-1/3)^2-1/9`

`=6 . 1/9 -1/9`

`=6/9-1/9`

`=5/9`

`3, (1/5)^5 : (1/5)^3 - (-1/3)^3 : (-1/3)^2`

`=1/5^(5-3) - (-1/3)^(3-2)`

`=1/5^2 - (-1/3)`

`=1/25 +1/3`

`=28/75`

`4, (1-2/3 +1/2)-(2+1/3-1,5)`

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

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

`=-1-1+2`

`=-2+2`

`=0`