Câu 1. (2 điểm) Thực hiện phép tính (tính bằng cách hợp lý nếu có thể): a) $\frac{1}{5}$ - $\frac{13}{19}$ - $\frac{3}{4}$ + $\frac{4}{5}$ - $\frac{6}{19}$ b) $\frac{5}{9}$ : ($\frac{1}{2}$ + $\frac{-5}{22}$) + $\frac{5}{9}$ : ($\frac{1}{5}$ + $\frac{8}{35}$) c) $\frac{3}{5}$.$\frac{6}{7}$ + $\frac{3}{7}$ : $\frac{5}{3}$ - $\frac{2}{7}$ : 1$\frac{2}{3}$ d) |$\frac{-5}{8}$|.$\sqrt[]{64}$ - $2022^{0}$.$\sqrt[]{\frac{16}{25}}$

Đáp án+Giải thích các bước giải:

 `a)`

`1/5-13/19-3/4+4/5-6/19`

`=(-13/19-6/19)+(1/5+4/5)-3/4`

`=-19/19+5/5-3/4`

`=-1+1-3/4`

`=(1-1)-3/4`

`=0-3/4`

`=-3/4`

`b)`

`5/9:(1/2+\frac{-5}{22})+5/9:(1/5+8/35)`

`=5/9:(11/22-5/22)+5/9:(7/35+8/35)`

`=5/9: 6/22+5/9: 15/35`

`=5/9:3/11+5/9:3/7`

`=5/9. 11/3+5/9. 7/3`

`=5/9. (11/3+7/3)`

`=5/9. 18/3`

`=5/9. 6`

`=30/9`

`=10/3`

`c)`

`3/5. 6/7+3/7: 5/3-2/7: 1 2/3`

`=3/5. 6/7+3/7. 3/5-2/7: 5/3`

`=3/5.(6/7+3/7)-2/7. 3/5`

`=3/5.(9/7-2/7)`

`=3/5. 7/7`

`=3/5. 1`

`=3/5`

`d)`

`|\frac{-5}{8}|.\sqrt{64}-2022^{0}.\sqrt{16/25}`

`=5/8. 8-1.4/5`

`=5-4/5`

`=25/5-4/5`

`=21/5`