Cách viết nào sau đây cho ta một phân số:

$\dfrac{5}{8}$                         

$\dfrac{8}{{ - 5}}$                            

$\dfrac{{ - 5}}{8}$                          

$ - 5,8$

\(\dfrac{1}{2}\)              

\(\dfrac{1}{4}\)

\(\dfrac{3}{4}\)

\(\dfrac{5}{8}\)      

\(\dfrac{{ - 58}}{{73}}\) 

\(\dfrac{{58}}{{73}}\)            

\(\dfrac{{73}}{{ - 58}}\)           

\(\dfrac{{58}}{{73}}\)

\(\dfrac{4}{{10}}\)

\(\dfrac{{ - 6}}{{15}}\)  

\(\dfrac{6}{{15}}\)     

\(\dfrac{{ - 4}}{{ - 10}}\)

\(\dfrac{1}{3} = \dfrac{{45}}{{135}}\)          

\(\dfrac{{ - 13}}{{20}} = \dfrac{{26}}{{ - 40}}\)  

\(\dfrac{{ - 4}}{{15}} = \dfrac{{ - 16}}{{ - 60}}\)             

\(\dfrac{6}{7} = \dfrac{{ - 42}}{{ - 49}}\)

\(20\)

\( - 60\)  

\(60\)   

\(30\)

\(\dfrac{{100}}{{20}}\left( {{m^2}} \right)\) 

\(\dfrac{{20}}{{100}}\left( {{m^2}} \right)\)             

\(\dfrac{{20}}{{10}}\left( {{m^2}} \right)\)

\(\dfrac{{20}}{{1000}}\left( {{m^2}} \right)\)