Câu 1 (1,5 điểm) Thực hiện phép tính: a) $\frac{12}{17}$ - $\frac{2}{9}$ + $\frac{5}{17}$ - $\frac{7}{9}$ b) $\frac{11}{3}$. $\frac{8}{13}$ + $\frac{5}{13}$.$\frac{22}{6}$ - $\frac{2}{3}$ c) $\frac{5}{3}$ : [(5,22 - 0,02).$\frac{\sqrt[]{25}}{26}$] - |-$\frac{1}{2}$|

Đáp án+Giải thích các bước giải:

 `a)`

`12/17-2/9+5/17-7/9`

`=(12/17+5/17)-(2/9+7/9)`

`=17/17-9/9`

`=1-1`

`=0`

`b)`

`11/3. 8/13+ 5/13. 22/6-2/3`

`=11/3. 8/13+\frac{5.22}{13.6}-2/3`

`=\frac{11.8}{3.13}+\frac{5.11.2}{13.6}-2/3`

`=\frac{11}{3}. 8/13+\frac{11}{3}. 5/13-2/3`

`=11/3.(8/13+5/13)-2/3`

`=11/3. 13/13-2/3`

`=11/3. 1-2/3`

`=11/3- 2/3`

`=9/3`

`=3`

`c)`

`5/3:[(5,22-0,02).\frac{\sqrt{25}}{26}]-|-1/2|`

`=5/3:(5,2.\frac{5}{26})-1/2`

`=5/3:(26/5. 5/26)-1/2`

`=5/3: 1-1/2`

`=5/3-1/2`

`=10/6-3/6`

`=7/6`