Bài 84 trang 43 SGK Toán 6 tập 2

Tính: 

a) \(\dfrac{-5}{6}:\dfrac{3}{13}\) ;              

b) \(\dfrac{-4}{7}:\dfrac{-1}{11}\) ;              

c) \(-15:\dfrac{3}{2}\) ;

d) \(\dfrac{9}{5}:\dfrac{-3}{5}\) ;                

e) \(\dfrac{5}{9}:\dfrac{5}{-3}\) ;                  

g) \(0:\dfrac{-7}{11}\) ;

h) \(\dfrac{3}{4}:(-9)\). 

a) \(\dfrac{-5}{6}:\dfrac{3}{13} = \dfrac{-5}{6}.\dfrac{13}{3}\) = \(\dfrac{-65}{18}\) ;                    

b)\(\dfrac{-4}{7}:\dfrac{-1}{11} = \dfrac{-4}{7}.\dfrac{-11}{1}\) =  \(\dfrac{44}{7}\) ;                          

c) \(-15:\dfrac{3}{2} = -15.\dfrac{2}{3} \)\(=\dfrac{-30}{3} =-10\) 

d) \(\dfrac{9}{5}:\dfrac{-3}{5}= \dfrac{9}{5}.\dfrac{-5}{3} =-3\)                        

e) \(\dfrac{5}{9}:\dfrac{5}{-3} = \dfrac{5}{9}.\dfrac{-3}{5}\) = \(\dfrac{-1}{3}\)                             

g) \(0:\dfrac{-7}{11}=0\)  ;

h) \(\dfrac{3}{4}:(-9) =\dfrac{3}{4}. \dfrac{-1}{9} \) = \(\dfrac{-1}{12}\).