Tính $\dfrac{2}{3}:\dfrac{7}{{12}}:\dfrac{4}{{18}}$

$1$ 

$3$  

$\dfrac{1}{{ - 3}}$    

$\dfrac{1}{3}$

$\dfrac{{ - 2}}{{27}}$                     

$\dfrac{{ - 4}}{9}$  

$\dfrac{{ - 1}}{{18}}$

$\dfrac{{ - 3}}{2}$

$\dfrac{1}{4}$ 

$\dfrac{1}{2}$          

$- \dfrac{1}{2}$                        

$1$

${\left( {\dfrac{{ - 7}}{6}} \right)^2} = \dfrac{{ - 49}}{{36}}$ 

${\left( {\dfrac{2}{3}} \right)^3} = \dfrac{8}{9}$  

${\left( {\dfrac{2}{{ - 3}}} \right)^3} = \dfrac{8}{{ - 27}}$          

${\left( {\dfrac{{ - 2}}{3}} \right)^4} = \dfrac{{ - 16}}{{81}}$

$- \dfrac{1}{{10}}$ 

$- \dfrac{4}{9}$  

$- \dfrac{4}{3}$                               

$- 4$

$8$ 

$\dfrac{9}{5}$  

$\dfrac{3}{5}$          

$2$