Bài 1. (1,5 điểm) Thực hiện phép tính a) M = $\frac{2}{15}$. $\frac{3}{7}$+ $\frac{2}{15}$. $\frac{18}{7}$  b) N = $-8.(\frac{1}{4})^2$ + $|-\frac{1}{3}|$ : $\sqrt{\frac{1}{9}}$  c) Q = $\frac{5}{11}$. $\frac{2}{17}$+ $\frac{7}{17}$. $\frac{-6}{11}$- $\frac{9}{17}$. $\frac{5}{11}$ 

`a)M=2/15. 3/7+2/15. 18/7`

`=2/15. (3/7+18/7)`

`=2/15. 3`

`=2/5`

Vậy `M=2/5`

`b)N=-8.((-1)/4)^2+|-1/3|:\sqrt{1/9}`

`=-8. 1/16+1/3:1/3`

`=-1/2+1`

`=1/2`

Vậy `N=1/2`

`c)Q=5/11. 2/17+7/17.(-6)/11-9/17. 5/11`

`=5/11.(2/17-9/17)+(-7/17). 6/11`

`=5/11.(-7/17)+(-7/17). 6/11`

`=-7/17. (5/11+6/11)`

`=-7/17. 1`

`=-7/17`

Vậy `Q=-7/17`